Name: Hussain Ali
Registration No. : 2018-CH-237
Section: A
Lab Report
Submitted To: Sir Suliaman
Instrumentation and Control Lab
(Ch. E-404L)
Page | 1
Table of Contents
Lab instructor and course learning outcome ........................................................................................... 7
General Safety Instruction ......................................................................................................................... 8
General Safety Instruction for Electrical Equipment ............................................................................. 9
The COSHH Regulations ......................................................................................................................... 10
Report Rubrics (CLO-2)........................................................................................................................... 11
Laboratory Performance Assessment Rubrics (CLO-1)........................................................................ 12
Viva Voice Rubrics (CLO-1, CLO-2 & CLO-3)..................................................................................... 13
Equipment status in Instrumentation and Control Lab ........................................................................ 14
List of Utilities for instrumentation and control Lab ............................................................................. 14
List of consumables for instrumentation and control Lab..................................................................... 14
Experiment No. 1 ...................................................................................................................................... 15
Thermocouple............................................................................................................................................ 15
Objective: ............................................................................................................................................... 15
Apparatus: ............................................................................................................................................. 15
Theory: ................................................................................................................................................... 15
Procedure: ............................................................................................................................................. 19
Safety Precautions: ............................................................................................................................... 19
Observations and Calculations: ........................................................................................................... 19
Graphs: .................................................................................................................................................. 20
Discussion: ............................................................................................................................................. 21
References: ................................................................................................................................................ 21
Experiment No. 2 ...................................................................................................................................... 22
Temperature Bench Measurement .......................................................................................................... 22
Objective: ............................................................................................................................................... 22
Apparatus: ............................................................................................................................................. 22
Theory: ................................................................................................................................................... 22
Applications:.......................................................................................................................................... 25
Safety Precautions: ............................................................................................................................... 26
Procedure: ............................................................................................................................................. 26
Observation and Calculations: ............................................................................................................ 26
Discussion: ............................................................................................................................................. 27
References .................................................................................................................................................. 27
Experiment No. 3 ...................................................................................................................................... 28
Temperature Bench Measurement .......................................................................................................... 28
Objective: ............................................................................................................................................... 28
Page | 2
Apparatus: ............................................................................................................................................. 28
Theory: ................................................................................................................................................... 28
Safety Precautions: ............................................................................................................................... 32
Procedure: ............................................................................................................................................. 32
Observation and Calculations: ............................................................................................................ 32
Graph: .................................................................................................................................................... 33
Discussion: ............................................................................................................................................. 33
References: ................................................................................................................................................ 33
Experiment No. 4 ...................................................................................................................................... 34
Dead Weight Pressure Gauge Calibrator ............................................................................................... 34
Objective: ............................................................................................................................................... 34
Experimental Setup: ............................................................................................................................. 34
Apparatus: ............................................................................................................................................. 34
Theory: ................................................................................................................................................... 34
Experimental Procedure: ..................................................................................................................... 38
Safety Precautions: ............................................................................................................................... 39
Observation and Calculation: .............................................................................................................. 39
Graph: .................................................................................................................................................... 40
Discussion: ............................................................................................................................................. 40
References: ................................................................................................................................................ 40
Experiment No. 5 ...................................................................................................................................... 41
Liquid Level System ................................................................................................................................. 41
Objective: ............................................................................................................................................... 41
Apparatus: ............................................................................................................................................. 41
Theory: ................................................................................................................................................... 41
Procedure: ............................................................................................................................................. 43
Safety Precautions: ............................................................................................................................... 44
Observations and Calculations: ........................................................................................................... 44
References:............................................................................................................................................. 46
Experiment No. 6 ...................................................................................................................................... 47
Liquid Controller Rig ............................................................................................................................... 47
Objective: ............................................................................................................................................... 47
Apparatus: ............................................................................................................................................. 47
Procedure: ............................................................................................................................................. 47
Safety Precautions: ............................................................................................................................... 47
Experiment No. 7 ...................................................................................................................................... 48
Page | 3
PLC Control (Flow Control) .................................................................................................................... 48
Objective: ............................................................................................................................................... 48
Apparatus: ............................................................................................................................................. 48
Theory: ................................................................................................................................................... 48
Procedure: ............................................................................................................................................. 52
Safety Precautions: ............................................................................................................................... 52
Observations and Calculations: ........................................................................................................... 53
References: ................................................................................................................................................ 53
Experiment No. 8 ...................................................................................................................................... 54
PLC Control (Pressure Control) ............................................................................................................. 54
Objective: ............................................................................................................................................... 54
Apparatus: ............................................................................................................................................. 54
Theory: ................................................................................................................................................... 54
Procedure: ............................................................................................................................................. 58
Safety Precautions: ............................................................................................................................... 58
Observations and Calculations: ........................................................................................................... 59
References: ................................................................................................................................................ 59
Experiment No. 9 ...................................................................................................................................... 60
PLC Control (Temperature Control)...................................................................................................... 60
Objective: ............................................................................................................................................... 60
Apparatus: ............................................................................................................................................. 60
Theory: ................................................................................................................................................... 60
Procedure: ............................................................................................................................................. 64
Safety Precautions: ............................................................................................................................... 64
Observations and Calculations: ........................................................................................................... 65
References: ................................................................................................................................................ 65
Experiment No. 10 .................................................................................................................................... 66
PLC Control (Level Control) ................................................................................................................... 66
Objective: ............................................................................................................................................... 66
Apparatus: ............................................................................................................................................. 66
Theory: ................................................................................................................................................... 66
Procedure: ............................................................................................................................................. 70
Safety Precautions: ............................................................................................................................... 70
Observations and Calculations: ........................................................................................................... 71
References: ................................................................................................................................................ 71
Experiment No. 11 .................................................................................................................................... 72
Page | 4
Thermocouple K-type (Open Ended) ...................................................................................................... 72
Abstract: ................................................................................................................................................ 72
Objective: ............................................................................................................................................... 73
Apparatus: ............................................................................................................................................. 73
Reagents:................................................................................................................................................ 73
Theory: ................................................................................................................................................... 73
Procedure: ............................................................................................................................................. 77
Safety Precautions: ............................................................................................................................... 77
Observations & Calculations: .............................................................................................................. 78
Graphs: .................................................................................................................................................. 79
.................................................................................................................................................................... 80
.................................................................................................................................................................... 80
.................................................................................................................................................................... 81
Discussion: ............................................................................................................................................. 81
Conclusion: ............................................................................................................................................ 82
Reference: .................................................................................................................................................. 82
Experiment No. 12 .................................................................................................................................... 83
Instrumentation & Control on Mass Transfer Lab ............................................................................... 83
Equipment No: 01 ................................................................................................................................. 83
Diagram: ................................................................................................................................................ 83
Instrumentation & Control:................................................................................................................. 83
Description: ........................................................................................................................................... 83
Equipment No: 02 ................................................................................................................................. 85
Diagram: ................................................................................................................................................ 85
Instrumentation & Control:................................................................................................................. 86
Description: ........................................................................................................................................... 86
Equipment No: 03 ................................................................................................................................. 88
Diagram: ................................................................................................................................................ 88
Instrumentation & Control:................................................................................................................. 89
Description: ........................................................................................................................................... 89
Equipment No: 04 ................................................................................................................................. 89
Diagram: ................................................................................................................................................ 90
Instrumentation & Control:................................................................................................................. 90
Description: ........................................................................................................................................... 90
Equipment No: 05 ................................................................................................................................. 92
Diagram: ................................................................................................................................................ 92
Page | 5
Instrumentation & Control:................................................................................................................. 92
Description: ........................................................................................................................................... 93
Equipment No: 06 ................................................................................................................................. 93
Diagram: ................................................................................................................................................ 93
Instrumentation & Control:................................................................................................................. 94
Description: ........................................................................................................................................... 94
Equipment No: 07 ................................................................................................................................. 95
Diagram: ................................................................................................................................................ 96
Instrumentation & Control:................................................................................................................. 96
Description: ........................................................................................................................................... 96
Equipment No: 08 ................................................................................................................................. 97
Diagram: ................................................................................................................................................ 97
Instrumentation & Control:................................................................................................................. 97
Description: ........................................................................................................................................... 97
References:............................................................................................................................................. 99
Page | 6
Lab instructor and course learning outcome
Course Type
Semester
Compulsory,8th
Lab. Schedule
Timetable
Credit Hours
One
Pre-requisite
None
Sir Sulaiman
Contact
m.sulaiman@uet.edu.pk
Instructor
Ground Floor
Biomedical
Department
Office
Teaching
Assistant
None
Office Hours
Lab Schedule
Monday 1:00 PM to 4:00
PM
One credit hour
(1) Evaluate the time constant of given Thermocouple (K-Type) and also find out
its response, of the system when t = τ, t = 2 τ, t = 3 τ.
(2) Calibrate the given resistance temperature detector (RTD) using the mercury
Experiments
Description
filled thermometer.
(3) Calibrate the given thermocouple with the help of potentiometer.
(4) To calibrate the readings of Bourdon manometers and to determine the gauge error.
(5) Determination of the Time Constant of the given liquid level system
Measurable Learning Outcomes
(6) Analyze the dynamic behavior of first order ON/OFF level control system
Page | 7
CLOs
Description
PLOs
Level
CLO1
Performs calibration of various process
instruments and PLC control system for
estimating the dynamic behavior and error
assessment
PLO-4
P-3
CLO2
Report results in an ethical manner
PLO-8
A-2
CLO3
Describe various practical related process
instruments and control variables and trends
PLO-2
C-2
General Safety Instruction
1. Never eat or drink while working in the laboratory.
2. Read labels carefully.
3. Do not use any equipment unless you are trained and approved as a user by your supervisor.
4. Wear safety glasses or face shields when working with hazardous materials and/or
equipment.
5. Wear gloves when using any hazardous or toxic agent.
6. Clothing: When handling dangerous substances, wear gloves, laboratory coats, and safety
shield or glasses. Shorts and sandals should not be worn in the lab at any time. Shoes are
required when working in the machine shops
7. If you have long hair or loose clothes, make sure it is tied back or confined.
8. Keep the work area clear of all materials except those needed for your work. Coats should
be hung in your room or placed in a locker. Extra books, purses, etc. should be kept away
from equipment that requires air flow or ventilation to prevent overheating
9. Disposal - Students are responsible for the proper disposal of used material if any in
appropriate containers
10. Equipment Failure - If a piece of equipment fails while being used, report it immediately a
technician. Never try to fix the problem yourself because you could harm yourself and
others.
11. If leaving a lab unattended, turn off all ignition sources and lock the doors.
12. Clean up your work area before leaving.
13. Wash hands before leaving the lab and before eating.
Page | 8
General Safety Instruction for Electrical
Equipment
1. Obtain permission by the Lab Incharge before operating any high voltage equipment
(voltages above 50Vrms ac and 50V dc are always dangerous, extra precautions should be
considered as voltage levels are increased)
2. Maintain an unobstructed access to all electrical panels.
3. Avoid using extension cords whenever possible. Extension cords should not go under
doors, across aisles, be hung from the ceiling, or plugged into other extension cords.
4. Never, ever modify or otherwise change any high voltage equipment.
5. before attaching the power supply to your setup make sure there are no “live” wires which
can be touched when possible use a box with an interlock
6. when attaching a high voltage power supply ALWAYS switch off the supply W
7. When you are adjusting any high voltage equipment or a laser which is powered with a
high voltage supply, USE ONLY ONE HAND. Your other hand is best placed in a pocket
or behind your back. This procedure eliminates the possibility of an accident where high
voltage current flows up one arm, through your chest, and down the other arm.
Page | 9
The COSHH Regulations
The Control of Substances Hazardous to Health Regulations (1988):
The COSHH regulations impose a duty on employers to protect employees and others from
substances used to work which may be hazardous to health. The regulations require you to make
an assessment of all operations which are liable to expose any person to hazardous solids, liquids,
dusts, vapors, gases or micro-organisms. You are also required to introduce suitable procedures
for handling these substances and keep appropriate records. Part of the above regulations are to
ensure that the relevant Health and Safety Data Sheets are available for all hazardous substances
used in the laboratory. Any person using a hazardous substance must be informed of the following:
1. Physical data about the substance
2. Any hazard from fire or explosion
3. Any hazard to health
4. Appropriate First Aid treatment.
5. Any hazard from reaction with other substances.
6. How to clean/dispose of spillage.
7. Appropriate protective measures.
8. Appropriate storage and handling.
Although these regulations may not be applicable in your country, it is strongly recommended
that a similar approach is adopted for the protection of the students operating the equipment. Local
regulations must be considered.
Page | 10
Report Rubrics (CLO-2)
Assessment
Criteria
(%Weightage)
Objective (10%)
Acceptable (5 – 7)
Unsatisfactory (0 – 3)
Clear, briefly and specific
Purpose established broadly.
Not or poorly presented.
Brief background theories and
laws have been concisely
described with references as
per objective.
Broad description of
background theories and
laws with no link to the
objective.
Background theories and laws with
irrelevant data has been described with
improper referencing.
Experiment
procedure (10%)
Well described in the
appropriate steps in logical
manner.
Described in disorder or a
very short way.
Description of procedure with missing
steps or not presented at all
Result and
Discussion (40%)
Present all the results needed
for the report in an
appropriate manner.
Introduction
(10%)
Page | 11
Excellent (8 – 10)
Present the results partially.
Not presented at all
Conclusions (20%)
Very well redacted and
meaningful conclusions.
Presentation of a summary
or other parts of the report as
conclusions
Not presented at all or not related in any
way with the lab.
Safety Precautions
(10%)
Proper safety instruction are
listed
Incomplete safety instruction
Safety precautions are not presented
Laboratory Performance Assessment Rubrics (CLO-1)
Grading
Assessment Criteria (Weightage)
Excellent
(9 – 10)
Good
(7 – 8)
Can perform all
steps with
sequence but
Don’t know their
rationale.
Experiment Performance
(30%)
Can perform all
steps with sequence
and their logic to
achieve an objective
Result, Discussion and Analysis
(40%)
Can critically and
logically analyze
the result of an
experiment
Can critically
analyze the result
of an experiment
Have general and
experiment specific
awareness of lab
safety and practice
it.
Have general
awareness of lab
safety and
practice it. Have
experiment
specific safety
awareness but
don’t practice it.
Safety Measures
(30%)
Page | 12
Average
(5 – 6)
Weak
(3 – 4)
Fail
(0 – 2)
Can recall all
steps with
sequence and
rationale.
Can recall
few steps
with
sequence
Cannot recall
some or no
steps and their
sequence.
Can simply
describe the
result of an
experiment
Have general
awareness of
lab safety and
practice it.
But don’t
have
experiment
specific
Safety
awareness.
Can
generically
describe the
result
Cannot be able
to describe the
result
Have general
awareness of
Lab safety
but don’t
practice
Have no
awareness of
safety measures
for the
experiment
Evaluation
Viva Voice Rubrics (CLO-1, CLO-2 & CLO-3)
Grading
Assessment Criteria
(Weightage)
Knowledge of
experiment
performance and
demonstration
(50%) (CLO-1)
Report assessment
(40%) (CLO-2)
Communication Skills
(10%) (CLO-3)
Page | 13
Excellent
(9-10)
Good
(7-8)
Average
(5-6)
Weak
(3-4)
Fail
(0-2)
Candidate has
Candidate has
Candidate has
Candidate has
Candidate
excellent knowledge sufficient knowledge
reasonable
meager
doesn’t know
of experiment
of experiment
knowledge of
knowledge of how to perform
performance and
performance and
experiment
experiment
and
demonstration
demonstration
performance and performance and demonstrate
demonstration
demonstration the experiment
Candidate has
Candidate has
complete knowledge sufficient knowledge
of all the features
of all the features
written in the report written in the report
Student uses a clear
body language and
well answered to all
the questions
Student uses a
good body
language and
sufficiently given
the answers to all
the questions
Candidate
lacks while
explaining the
main report
feature
Student uses
inappropriate
body language
and cannot be
able to answers
to all the
questions
Candidate
Candidate does
lacks a lot in not know the
explaining the main report
main report
features
feature
Students lack
a lot in
communicatin
g g the
answers to all
the questions
Student does
not able to
communicate
the answer of a
single question
Evaluation
Equipment status in Instrumentation and Control Lab
S. No.
Equipment
Quantity
Status
1
K Type Thermocouple
1
Working
1
Working
1
Working
1
Working
1
Working
2
3
4
5
Dead Weight Pressure
Gauge Calibrator
Temperature
Measurement Bench
through Resistance
Temperature
Detector
(RTD)
Temperature
Measurement Bench
through
Potentiometer
Level control Rig
(ON/OFF
controller)
6
Liquid level system
1
Working
7
PLC Trainer
1
Working
Remarks
List of Utilities for instrumentation and control Lab
1- Electricity
2- Oil
List of consumables for instrumentation and control
Lab
S.
No.
1
Page | 14
Chemicals
Hydraulic Oil
Required
Quantity
0 ml
Availabilit
y
700 ml
Experiment No. 1
Thermocouple
Objective:
Determination of the time constant of the given thermocouple (K-type) and also find out
the response “Tb” of the system when t=τ, t=2τ, t=3τ
Apparatus:

Thermocouple

Heater

Digital Voltmeter

Stop watch

Hookup wires
Theory:
A thermocouple consists of two wires of two different materials that are joined at each end.
When these two junctions are kept at different temperatures a small electric current is induced.
Due to the flow of current a voltage drop occurs. This voltage drop depends on the temperature
difference between the two junctions. The measurement of the voltage drop can then be correlated
to this temperature difference. It is extremely important to note that a thermocouple does not
measure the temperature, but rather the temperature difference between the two junctions. In order
to use a thermocouple to measure temperature directly, one junction must be maintained at a known
temperature. This junction is commonly called the reference junction (which is kept at 0℃ usually)
and its temperature is the reference temperature. The other junction, which is normally placed in
contact with the body of unknown temperature, is called the measurement junction.
Time constant 𝜏 is the time taken by the response function to register 63.2% of its ultimate value
is called time constant.
What is a Thermocouple?
A Thermocouple is a sensor used to measure temperature. Thermocouples consist of two
wire legs made from different metals. The wire’s legs are welded together at one end, creating a
junction. This junction is where the temperature is measured. When the junction experiences a
change in temperature, a voltage is created. The voltage can then be interpreted by calculating the
temperature.
Page | 15
How does a thermocouple work?
Two dissimilar metals are joined together at both ends in an electrical circuit. One
“junction” is the measuring junction or “hot end”. The other is the reference junction or “cold end”.
A sensitive voltmeter is connected into one of the conductors.
Under laboratory conditions the reference junction would be held at a known temperature,
usually 0°C but in normal industrial practice the junction is left at ambient temperature and an
external sensor is used to compensate for this variation (known as cold junction compensation,
usually a thermistor bead is used to measure the ambient temperature). Quite simply as the
temperature rises or falls at the measuring junction a voltage is generated within the circuit which
correlates directly to temperature and can easily be converted by reference to the appropriate
tables.
Thermocouple Working Principle:
The thermocouple principle mainly depends on the three effects namely See beck, Peltier
and Thompson.
See beck-effect:
This type of effect occurs among two dissimilar metals. When the heat offers to any one of
the metal wires, then the flow of electrons supplies from hot metal wire to cold metal wire.
Therefore, direct current stimulates in the circuit.
Peltier-effect:
This Peltier effect is opposite to the See beck-effect. This effect states that the difference
of the temperature can be formed among any two dissimilar conductors by applying the potential
variation among them.
Page | 16
Thompson-effect:
This effect states that as two disparate metals fix together & if they form two joints then
the voltage induces the total conductor’s length due to the gradient of temperature. This is a
physical word which demonstrates the change in rate and direction of temperature at an exact
position.
Types of thermocouples:
Various thermocouples are manufactured for different purposes, using a variety of metals.
The various types of popular thermocouples include:

Type K: the most common type of thermocouple, it is inexpensive, reliable and accurate

Type J: also, very common, but has a smaller temperature range and also has a shorter
lifespan at higher temperatures than the type K

Type T: a stable thermocouple and is used for lower temperatures

Type E: has a stronger signal and a higher accuracy

Type N: shares the same accuracy and limits as K but it slightly more expensive

Type S: for very high temperatures and is used mainly in the pharmaceutical industry
Page | 17

Type R: similar to type S in terms of performance and is often used in lower temperature
because of its accuracy and stability

Type B: has the highest temperature range out of all the thermocouples
Advantages & Disadvantages of Thermocouple:
The advantages include the following:

Accuracy is high

It is Robust and can be used in environments like harsh as well as high vibration.

Thermal reaction is fast

The operating range of temperature is wide.

Wide operating temperature range

Cost is low and extremely consistent.
The disadvantages include the following:

It has low-accuracy.

The thermocouple recalibration is hard
Thermocouple Applications:
Some of the applications of thermocouple include the following:

These are used as the temperature sensors in thermostats in offices, homes, offices &
businesses.

These are used in industries for monitoring temperatures of metals in iron, aluminum, and
metal.

These are used in the food industry for cryogenic and Low-temperature applications.
Thermocouples are used as a heat pump for performing thermoelectric cooling.

These are used to test temperature in the chemical plants, petroleum plants.

These are used in gas machines for detecting the pilot flame.
Page | 18
Procedure:
1. Position the Stand (without the thermocouple) on a table top and ensure that the base is
horizontal by using the spirit level.
2. Inert the thermocouple in the stand so that it can move easily.
3. Place the heater adjacent to the stand and ensure proper electrical supply to the heater.
4. Connect the wires of Voltmeter to the corresponding wires of thermocouple. After this, the
apparatus is ready to perform the experiment.
5. Ensure that circuit is complete as shown in schematic diagram using Digital Voltmeter.
6. Note the reading on digital voltmeter.
7. Switch on the heater. As thermocouple receives heat, digital voltmeter reading changes.
8. The ultimate value of temperature has been considered 200oC for this experiment.
9. The conversion chart of voltage to temperature for the K type thermocouple is given below.
10. The measuring junction of thermocouple to be heated till the voltage appears on volt meter
to the range of (5.328 to 5.735) and measure the time duration by stopwatch to reach this
voltage level for estimating the response time. It is the estimation of response time at t=τ.
11. Repeat this procedure for the remaining values of time constants and plot a graph as
mentioned above.
Safety Precautions:
1. Wear lab coats and closed shoes in laboratory premises
2. Ensure proper working of miniature circuit breakers (MCB)
3. Carefully insert the thermocouple in the stand.
4. Immediately switch off the heater if there is any spark in heater’s power plug.
Observations and Calculations:
Room Temperature = Ts = 37 oC
Ultimate value of temperature = T = 160 oC
Amplitude = A = T – Ts = 160 – 37 = 123 oC
Page | 19
Response
Response Time
of a system
-ln (1- (Tb* / A))
Tb* / A
= t/ τb
-29
0.2357
0.2687
11
-26
0.2113
0.2373
124
13
-24
0.1951
0.2170
04
139
16
-21
0.1707
0.1871
05
155
18
-19
0.1544
0.1677
06
169
21
-16
0.1300
0.1392
07
185
23
-14
0.1138
0.1208
08
198
25
-12
0.0975
0.1025
09
209
28
-9
0.0731
0.0759
10
219
30
-7
0.0569
0.0585
No. of
Time
Thermocouple
Obs
(t)
reading
(Sec)
(Tb)
01
90
(0C)
8
02
110
03
Graphs:
Page | 20
Tb-Ts=Tb*
(0C)
Discussion:
As we see above when the time is going to increase the response and temperature is going
to increase as temperature is increasing by heating the thermocouple placed in any liquid.
References:

Ltd, P. P. (n.d.). Process Parameters Ltd. Retrieved from Process Parameters Ltd:
https://www.processparameters.co.uk/about-process-parameters/

Pyrosales. (n.d.). Pyrosales. Retrieved from Pyrosales: https://www.pyrosales.com.au/about-us/

Instrumentation & Control Lab Manual
Page | 21
Experiment No. 2
Temperature Bench Measurement
Objective:
Calibrate the given resistance temperature detector (RTD) using the mercury bulb thermometer.
Apparatus:

Resistance thermometer device

Beaker

Oil

Heating device (hot plate)

Mercury filled thermometer

Multimeter
Theory:
Temperature measuring bench (Cussons Unit) is designed to demonstrate several
commonly used methods of temperature measurements, and provides the means for calibration
and accuracy comparisons of different methods. Features are providing so that many faults
commonly occurring in thermocouple systems can be demonstrated. In addition, the unit may be
used to be to provide a temperature measuring facility for use with other laboratory experiments.
Thermocouple:
It is one of the most electrical effective measuring device. When two dissimilar wires of
metals are joined together. An emf will exist between the two points A and B, which is primarily
a function of junction temperature (T). All thermocouple circuits must have at least two junctions.
If the temperature of one junction is known, then the temperature of the other junction may be
easily calculated using the thermoelectric properties of the materials. The known temperature is
called the reference temperature. It is common to use the temperature of ice as a reference
temperature (ice bath).
Page | 22
The relation when one junction is at 0 ˚C can be expressed mathematically as:
Log E=A log T + B
Where:
E = emf in microvolt
T = temperature in ˚C
A, B constants depending on the wire forming the junction.
The main components of the experimental setup are:
Thermocouple:
The thermocouple principle is that if two dissimilar wires are fused at each end (but
otherwise separated) and one end junction is heated to a higher temperature than the other, an emf
is produced causing a current to flow around the loop. The actual value of emf will be dependent
on the nature of the materials and the temperature difference between the two junctions.
When temperature is measured by thermocouple, that part of circuit which connects the
thermocouple to indicating instrument is as important a part of the measuring unit as the
thermocouple itself. Ideally, one end of the thermocouple (the cold junction) is kept at fixed
temperature (preferably 0 ˚C) so that the emf generated by the thermocouple at a given temperature
Page | 23
of the 'hot' junction is always the same. In practice, however, a cold junction is not always kept at
a UN varying temperature. Compensating leads are therefore employed to transmit to the
measuring instrument. With the minimum of error, a thermocouple signal from a cold junction
which is at an unknown temperature. For highly an accurate temperature measurement under
laboratory conditions, the thermocouple wires should be led into an ice flask-or similar constant
temperature source –from which connections are made to the instrument by pure copper wires. If
the cold junction is not at 0 ˚C, it should be remembered that the emf output must be connected to
follow the different temperature. The second thermocouple may be connected in series with hot
junction thermocouples, so that the cold junction effects at the terminals are cancelled out. The
second thermocouple then becomes the cold junction, and may be conveniently placed in the ice
path for 0 ˚C reference, when using mv digital indicator. The direct reading thermocouple
instruments modern commercial design suitable for practical applications with a minimum of error
and therefore employs automatic cold junction compensation.
Liquid expansion thermometers (liquid-in-glass thermometer):
The indication of a simple liquid-filled thermometer depends simply on the difference in
the coefficient of volumetric expansion of the filling liquid relative to the envelope containing it.
The thermometers supplied are mercury in glass type. The ranges and accuracies are given in the
specification for optimum accuracy the immersion depths specified should be adhered to. Although
relatively low cost and simple mercury in glass thermometers are capable of high orders of
accuracy over the designed temperature range. The thermometers supplied are general laboratory
grade but are of sufficient accuracy to provide a reference for calibration of the other temperature
sensing devices provided.
Electrical resistance temperature thermometers:
Electrical resistance thermometers work on principle that when metal wire is heated, its
Page | 24
electrical resistance increases progressively with increasing temperature. The relationship between
variations in the resistance of wire and the temperature can be determined for any given wire. By
measuring the resistance using a suitable bridge the temperature can be determined. In the cussons
unit a platinum resistance probe is provided together precision power supply and resistance
network giving a direct digital indication of the probe resistance in ohms. The temperature
/resistance characteristics of the probe supplied are as follows:
Resistance at 0˚ 100+ 0.1Ω
Temperature coefficient 0.385 Ω/˚C
Applications:
The applications of Resistance Temperature Detectors in various industries include:

In Automotive Industry – As audio amplifiers and engine oil temperature sensors.

In Communication and Instrumentation – As temperature sensors and amplifiers.

In Consumer Electronics – For small appliance controls and Fire Detectors.

In Industrial Electronics – For gas flow indicators and Plastic laminating equipment.

In Medical Electronics – For blood dialysis equipment and Infant incubators.
RTDs should be used when:

Stability and accuracy are a requirement of the customer’s specification.

Accuracy extends over a wide temperature range.

High degree of standardization is desirable.
Advantages of Resistance Temperature Detector (RTD):
The advantages of Resistance Temperature Detectors include:
1. Linearity over wide operating range
2. Wide temperature operating range
Page | 25
3. High temperature operating range
4. Interchangeability over wide range.
5. Good stability at high temperature
Disadvantages of Resistance Temperature Detector (RTD):
The disadvantages of Resistance Temperature Detectors include:
1. Low sensitivity
2. Higher cost than thermocouples
3. No point sensing
4. Affected by shock and vibration
5. Requires three or four-wire operation
Limitations of RTD:
In the RTD resistance, there will be an I2R power dissipation by the device itself that causes
a slight heating effect. This is called as self-heating in RTD. This may also cause an erroneous
reading. Thus, the electric current through the RTD resistance must be kept sufficiently low and
constant to avoid self-heating.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Carefully use the Avometer and hotplate.

Immediately switch off the hotplate if there is any spark in its power plug.
Procedure:
1. The resistance thermometer device is inserted in oil beaker which already had mercury
filled thermometer.
2. The oil in the beaker is heated and different sets of readings are taken for resistance (in
ohms) and temperature (oC) for every 5o C rise in temperature.
3. Finally, a graph between the temperature along X-axis and resistance along Y-axis is
plotted. The straight-line draw showed the fitness of the resistance thermometer under
consideration for the required purpose.
Observation and Calculations:
Page | 26
No. of
Temperature
Resistance
Observation
1
2
3
4
5
6
7
8
9
10
(0C)
60
70
80
90
100
110
120
130
140
150
(Ω)
3.2
3.4
3.7
3.9
4.2
4.6
4.9
5.1
5.4
5.6
Discussion:
As shown in graph the temperature increase, the resistance is also going to increase. As we
know that resistance is directly proportional to temperature so temperature increases, the resistance
of thermocouple also increase.
References

Hussein, E. (1987). Elemad 1987. Retrieved from https://sites.google.com/site/elemad1987/omda

Instrumentataion & Control Lab manual
Page | 27
Experiment No. 3
Temperature Bench Measurement
Objective:
Calibrate the given thermocouple with the help of potentiometer
Apparatus:

Potentiometer

Thermocouple

Oil bath

Mercury filled thermometer

Heating medium (Hot Plate)
Theory:
What is a Potentiometer?
A potentiometer (also known as a pot or potmeter) is defined as a 3 terminal variable
resistor in which the resistance is manually varied to control the flow of electric current. A
potentiometer acts as an adjustable voltage divider.
How Does a Potentiometer Work?
A potentiometer is a passive electronic component. Potentiometers work by varying the
position of a sliding contact across a uniform resistance. In a potentiometer, the entire input voltage
is applied across the whole length of the resistor, and the output voltage is the voltage drop between
the fixed and sliding contact as shown below:
Page | 28
A potentiometer has the two terminals of the input source fixed to the end of the resistor.
To adjust the output voltage the sliding contact gets moved along the resistor on the output side.
This is different to a rheostat, where here one end is fixed and the sliding terminal is connected to
the circuit. This is a very basic instrument used for comparing the emf of two cells and for
calibrating ammeter, voltmeter, and watt-meter. The basic working principle of a potentiometer is
quite simple. Suppose we have connected two batteries in parallel through a galvanometer. The
negative battery terminals are connected together and positive battery terminals are also connected
together through a galvanometer.
Potentiometer Types:
There are two main types of potentiometers:

Rotary potentiometer

Linear potentiometer
Although the basic constructional features of these potentiometers vary, the working principle
of both of these types of potentiometers is the same.
Rotary potentiometer:
The rotary type potentiometers are used mainly for obtaining adjustable supply voltage to
a part of electronic circuits and electrical circuits. The volume controller of a radio transistor is a
popular example of a rotary potentiometer where the rotary knob of the potentiometer controls the
supply to the amplifier.
Page | 29
This type of potentiometer has two terminal contacts between which a uniform resistance
is placed in a semi-circular pattern. The device also has a middle terminal which is connected to
the resistance through a sliding contact attached with a rotary knob. By rotating the knob one can
move the sliding contact on the semi-circular resistance. The voltage is taken between a resistance
end contact and the sliding contact. The potentiometer is also named as the POT in short. POT is
also used in substation battery chargers to adjust the charging voltage of a battery. There are many
more uses of rotary type potentiometer where smooth voltage control is required.
Linear Potentiometers:
The linear potentiometer is basically the same but the only difference is that here instead
of rotary movement the sliding contact gets moved on the resistor linearly. Here two ends of a
straight resistor are connected across the source voltage. A sliding contact can be slide on the
resistor through a track attached along with the resistor. The terminal connected to the sliding is
connected to one end of the output circuit and one of the terminals of the resistor is connected to
the other end of the output circuit.
This type of potentiometer is mainly used to measure the voltage across a branch of a
circuit, for measuring the internal resistance of a battery cell, for comparing a battery cell with a
standard cell and in our daily life, it is commonly used in the equalizer of music and sound mixing
systems.
Measurement of Voltage by Potentiometer:
The principle of measuring voltage across a branch of a circuit with help of a potentiometer
is also simple. Here first we have to adjust the rheostat to adjust the current through the resistor so
that it causes a specific voltage drop per unit length of the resistor. Now we have to connect one
end of the branch to the beginning of the resistor and other end is connected to the sliding contact
Page | 30
of the resistor through a galvanometer. Now we have to slide the sliding contact on the resistor
until the galvanometer shows zero deflection. When the galvanometer comes to its null condition
we have to take the reading of the position of the sliding contact tip on the resistor scale and
accordingly we can find out the voltage across the branch of the circuit since we have already
adjusted the voltage per unit length of the resistor.
Advantages of Digital Potentiometers:
The advantages of digital potentiometers are:

Higher reliability

Increased accuracy

Small size, multiple potentiometers can be packed on a single chip

Negligible resistance drift

Unaffected by environmental conditions like vibrations, humidity, shocks and wiper
contamination

No moving part

Tolerance up to ±1%

Very low power dissipation, up to tens of milliwatts
Disadvantages of Digital Potentiometers:
The disadvantages of digital potentiometers are:

Not suitable for high temperature environment and high power application.

Due to the parasitic capacitance of the electronic switches, there is a bandwidth
consideration that comes into the picture in digital potentiometers. It is the maximum signal
frequency that can cross the resistance terminals with less than 3 dB attenuation in the
wiper. The transfer equation is similar to that of a low pass filter.

The nonlinearity in the wiper resistance adds a harmonic distortion to the output signal.
The total harmonic distortion, or THD, quantifies the degree to which the signal is degraded
Page | 31
after crossing through the resistance.
Applications of Potentiometer:
There are many different uses of a potentiometer. The three main applications of a
potentiometer are:

Comparing the emf of a battery cell with a standard cell

Measuring the internal resistance of a battery cell

Measuring the voltage across a branch of a circuit
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Carefully use the thermocouple and hotplate.

Immediately switch off the hotplate if there is any spark in its power plug.
Procedure:
1. Connect the thermocouple with the mercury filled thermometer.
2. Insert both instrument in the beaker containing oil in it.
3. The oil in the beaker is heated till the temperature reaches to 180oC and the variation in
EMF is noted by rising the temperature with regular interval.
4. The change in emf along with the change in temperature is plotted on a graph paper. If the
line is linear then thermocouple is suitable for the required job.
Observation and Calculations:
No. of Obs
Temperature
(0C)
Electromotive Force (m
volts)
1
2
3
4
5
6
7
8
9
10
11
40
0.03
50
0.06
60
0.09
70
1.40
80
1.80
90
2.20
100
2.70
110
3.00
120
3.30
130
3.80
140
4.20
Page | 32
Graph:
Discussion:
As shown in graph as the temperature is going to increase the voltage also increase. In start
the voltage is contant and then it going to increase with increase in temperature.
References:

electrical4u. (n.d.). electrical4u. Retrieved from https://www.electrical4u.com/potentiometer/

I&C Lab Manual
Page | 33
Experiment No. 4
Dead Weight Pressure Gauge Calibrator
Objective:
To calibrate the reading of bourdon manometer and to determine the gauge error. Determine the
measurement error in reference pressure source used for calibration
Experimental Setup:
Schematic Diagram of Dead weight pressure gauge calibrator
Apparatus:

Manometric Calibrators

Set of masses.
Theory:
A dead weight tester is an instrument that calibrates pressure by determining the weight of force
divided by the area the force is applied. The formula for dead weight testers is pressure equals
force divided by area of where force is applied.
Page | 34
Dead weights are usually used for pressure gauge calibration as they come with high
accuracy, So they can be used as primary standard (as mentioned before).there are many types of
them depending on the application and they are operated with oil (hydraulic) or with air
(pneumatic). Dead weight testers are the basic primary standard for accurate measurement of
pressure. Dead weight testers are used to measure the pressure exerted by gas or liquid and can
also generate a test pressure for the calibration of numerous pressure instruments.
Why dead weight tester called dead weight tester?
In dead weight tester, we put the weight on the weight stand of dead weight tester putting
weight is reference weight which is to be calibrate and further we applied pressure by moving
piston ,when applied pressure and reference weight(Pressure)is equal at this condition reference
weight will be zero(Dead). Therefore it is called dead weigh tester.
A deadweight tester (DWT) is a calibration standard which uses a piston cylinder on which
a load is placed to make an equilibrium with an applied pressure underneath the piston.
The formula to design a DWT is based basically is expressed as follows:
p=F/A
[Pa]
Working of Dead Weight Tester:
1. Hand pump
2. Testing Pump
3. Pressure Gauge to be calibrated
4. Calibration Weight
5. Weight Support
Page | 35
6. Piston
7. Cylinder
8. Filling Connection
Basics:
Dead weight testers are a piston-cylinder type measuring device. As primary standards,
they are the most accurate instruments for the calibration of electronic or mechanical pressure
measuring instruments. They work in accordance with the basic principle that P= F/A, where the
pressure (P) acts on a known area of a sealed piston (A), generating a force (F). The force of this
piston is then compared with the force applied by calibrated weights. The use of high quality
materials result in small uncertainties of measurement and excellent long term stability.
Dead weight testers can measure pressures of up to 10,000 bar, attaining accuracies of
between 0.005% and 0.1% although most applications lie within 1 – 2500 bar. The pistons are
partly made of tungsten carbide (used for its small temperature coefficient), and the cylinders must
fit together with a clearance of no more than a couple of micrometers in order to create a minimum
friction thus limiting the measuring error. The piston is then rotated during measurements to further
minimize friction. The testing pump (2) is connected to the instrument to be tested (3), to the actual
measuring component and to the filling socket. A special hydraulic oil or gas such as compressed
air or nitrogen is used as the pressure transfer medium. The measuring piston is then loaded with
calibrated weights (4). The pressure is applied via an integrated pump (1) or, if an external pressure
supply is available, via control valves in order to generate a pressure until the loaded measuring
piston (6) rises and ‘floats’ on the fluid. This is the point where there is a balance between pressure
and the mass load. The piston is rotated to reduce friction as far as possible. Since the piston is
spinning, it exerts a pressure that can be calculated by application of a derivative of the formula
P = F/A.
The accuracy of a pressure balance is characterized by the deviation span, which is the sum
of the systematic error and the uncertainties of measurement. Today’s dead weight testers are
highly accurate and complex and can make sophisticated physical compensations. They can also
come accompanied by an intelligent calibrator unit which can register all critical ambient
parameters and automatically correct them in real time making readings even more accurate.
Operation Procedure:
The dead weight tester apparatus consists of a chamber which is filled with oil free
Page | 36
impurities and a piston – cylinder combination is fitted above the chamber as shown in diagram.
The top portion of the piston is attached with a platform to carry weights. A plunger with a handle
has been provided to vary the pressure of oil in the chamber. The pressure gauge to be tested is
fitted at an appropriate plate. The dead weight tester is basically a pressure producing and pressure
measuring device. It is used to calibrate pressure gauges.
The following procedure is adopted for calibrating pressure gauges. Calibration of pressure
gauge means introducing an accurately known sample of pressure to the gauge under test and then
observing the response of the gauge. In order to create this accurately known pressure, the
following steps are followed. The valve of the apparatus is closed.
A known weight is placed on the platform. Now by operating the plunger, fluid pressure is
applied to the other side of the piston until enough force is developed to lift the piston-weight
combination. When this happens, the piston weight combination floats freely within the cylinder
between limit stops. In this condition of equilibrium, the pressure force of fluid is balanced against
the gravitational force of the weights puls the friction drag.Therefore,
PA = Mg + F
P = Mg + F / A
Where, P = pressure
M = Mass; Kg
g = Acceleration due to gravity; m/s²
F = Friction drag; N
A = Equivalent area of piston – cylinder combination; m²
Thus the pressure P which is caused due to the weights placed on the platform is calculated.
After calculating P, the plunger is released. Now the pressure gauge to be calibrated is fitted at an
appropriate place on the dead weight tester. The same known weight which was used to calculate
Page | 37
P is placed on the platform. Due to the weight, the piston moves downwards and exerts a pressure
P on the fluid. Now the valve in the apparatus is opened so that the fluid pressure P is transmitted
to the gauge, which makes the gauge indicate a pressure value. This pressure value shown by the
gauge should be equal to the known input pressure P. If the gauge indicates some other value other
than p the gauge is adjusted so that it reads a value equal to p. Thus the gauge is calibrated.
Applications:
It is used to calibrated all kinds of pressure gauges such as industrial pressure gauges,
pressure transmitters etc.
Advantages:

It is simple in construction and easy to use. It can be used to calibrate a wide range of
pressure measuring devices.

Fluid pressure can be easily varied by adding weights or by changing the piston cylinder
combination.
Limitations:
The accuracy of the dead weight tester is affected due to the friction between the piston
and cylinder, and due to the uncertainty of the value of gravitational constant ‘g’.
Experimental Procedure:
1. Precision balance is required to determine the weight of piston and masses.
2. Place the equipment on a flat and even surface and connect the supply tube that connects
the inferior area of the cylinder to the input of the manometer. The output of this manometer
should be prolonged, by means of a flexible tube, from the drainage faucet until its free
end is settled inside an empty recipient to avoid splashes.
3. Disassemble the piston and determine accurately its weight and also determine the weight
of masses if it has not done yet.
Page | 38
4. Cover the piston with Vaseline for the best operation.
5. Open the faucet of the manometer, when the air of a system has been eliminated.
6. Now put the one-way valve in the flexible tune that comes from the supper part of a
cylinder. Later on, closed the output of the faucet of the manometer and introducing water
in the equipment.
7. Introduce the piston totally inside the cylinder.
8. Repeat these steps adding to the piston, in a staggering way, the different masses pf the
given sets of weights.
9. Once the test has been completed removed the piston and dry it.
10. Lastly empty the cylinder. Do not leave the piston inside the cylinder when it is not been
used.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Carefully use the thermocouple and hotplate.
Observation and Calculation:
Acceleration due to gravity = 9.8 m/sec2
Area of Piston =2.5446×10-4 m2
Initial error = 0.3
No. of
Mass of Piston
Pressure in the
Manometer
Manometer
Absolute
Relative
Observ.
(kg)
Cylinder
Reading
Reading
Error
Error (%)
(KN/m2)
(Bar)
(KN/m2)
(KN/m2)
1
0.5
19.26
0.2
20
0.74
3.7
2
1.0
39.52
0.5
50
11.48
22.96
3
2.5
96.30
1.2
120
23.7
19.75
4
5.0
192.61
2.2
220
27.39
12.45
Page | 39
Graph:
Discussion:
During this experiment as we increase the weight on piston, the pressure is going to increase. We
have to check that pressure gauge is working well or not, the weight we are placing having same value
shown on pressure gauge. If it’s shown same then it is working well.
References:

Reddy, S. B. (n.d.). Insta Tools. Retrieved from https://instrumentationtools.com/about/

Instrumentataion & Control Lab manual
Page | 40
Experiment No. 5
Liquid Level System
Objective:
Determination of the Time Constant of the given liquid level system
Apparatus:

Tanks

Tubes of different lengths, diameter and material Stop watch

Beaker

Graduated cylinder
Theory:
Liquid Level Control System:
Liquid Level Control System is a system specifically designed to control the level of fluid in tanks.
The main aim possessed by these systems is to control the rate with which the pump delivers fluid
to the tank and so it can reach the desired level inside the tank. The purpose of the liquid level
system is to maintain a specific level of fluid inside the tank. The liquid level control systems find
major applications in industrial processes.
Working of Liquid Level Systems:
The crucial components of the water level control system are as follows:

Fluid tank: Also known as a storage tank, used to hold the desired amount of fluid.

Measurement system: Senses the level of the fluid inside the tank.

Controller: The controller is used to maintain the desired level by starting and stopping the
pump when gets information by the measurement system.

Pump: The water from the source is fed to the tank through the pump when actuated by the
controller.
Page | 41
In such systems, fluid from the pump is allowed to enter the tank when the control signal is
generated by the controller.
Suppose, the controller actuates the pump and the pump starts filling the tank with an
inflow rate of Qi m3/s. Here H denotes the fluid level inside the tank in m and Qo be the outflow
rate of the fluid from the tank.
It is clear that to maintain a steady level of the liquid,
Qi = Qo
H = constant
But there exist some fluctuations in the rate of supply of the fluid. Basically, these systems are
analyzed on the basis of nature of the fluid flowing through the pipes. And this classification is
done on the basis of a number called Reynolds number. So, if the value of the Reynolds number
falls below 2000 then the flow is assumed to be laminar. This means that the fluid, in this case,
travels smoothly on a regular path. So, turbulence is not present in this type of flow.
While if the Reynolds number is more than 3000 to 4000 then, in this case, the flow is not laminar
but turbulent.
As we have already discussed in the beginning that these systems possess two main
purposes. The first is to maintain the liquid level and the second is the rate of flow of the liquid.
Thus, for the purpose of analysis, the two majorly concerned variables are the level of fluid in the
tank and the rate of flow of fluid through the pipes. So, resistance, capacitance and inertance are
regarded as the fundamental parameters of a liquid level control system. The term inertance
corresponds to the inertia forces which comes into action in order to cause acceleration of the fluid
through the pipes. It is regarded as an energy-storing element but the amount of stored energy due
Page | 42
to inertance is quite small thus is neglected at the time of analysis. So, the liquid level control
system is defined on the basis of only resistance and capacitance associated with the system.
Consider the figure we have shown above. And as we have mentioned that at steady state,
Qi = Qo
However, when the fluid outflows from the tank then there will be some resistance in its flow. The
amount of resistance offered depends on the outlet through which the fluid comes out.
In case of a hole as an outlet, the fluid will not flow out easily that causes the generation of
resistance. While in the case of the pipe as an outlet, the nature of flow which we have discussed
above i.e., laminar or turbulent and the frictional force between liquid and pipe are the deciding
factors for the resistance.
Also, the amount of offered resistance increases with the presence of the valve
With the pipe at the outlet. So, generally, the resistance of the liquid level system is expressed as:
This is defined on the basis of change noticed in the difference in levels of two tanks needed for
the unit change in the rate of flow of fluid. This means the ratio depends on the nature of the flow.
Procedure:
1. Take out one tube of certain length and diameter and fit it to the bottom of a tank.
2. Storage tank fill up to certain appropriate level.
3. A beaker is placed at the bottom of tank and remove the cork. The water begins to flow
downward and liquid level reach to a certain level, in the same time a stopwatch is used to
measure the time duration of the level change.
4. The volume of the water in the beaker is measured with the help of graduated cylinder.
Page | 43
5. The mean of the height or level of the water is also noted.
6. The storage of the tank can also be measured by measuring its diameter.
7. The same procedure is repeated to get the 5-6 reading.
8. Graph is plotted between mean level of water and flowrate; the slope of graph determines
the resistance.
9. The time constant of the system can be calculated by the formula; Time constant =
Resistance × Storage
10. The same procedure is repeated by changing.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Observe the liquid level carefully.
Observations and Calculations:
1st Run:
Length of the tube = 90 cm
Inner Diameter of tube = 1.3 cm
No. of
Initial level of
Final level of
Observa
the water
the water
(cm)
tions
(cm)
Mean
level
Volume
(ml)
Time
(sec)
(cm)
Flowrate=
Volume/time
(ml/sec)
1
14
13
13.5
1000
20.43
48.94
2
13
12
12.5
2000
41.24
48.49
3
12
11
11.5
300
62.00
48.30
Graph 1:
Page | 44
Slope = Resistance =R= 0.32 sec/cm2
Storage= πD2/4= 1.327 cm2
Time Constant = R × Storage
2nd Run:
Length of the tube = 70 cm
Inner Diameter of tube = 1.3 cm
No. of
Initial level of
Final level of
Observa
the water
the water
(cm)
-tions
(cm)
Mean
level
Volume
(ml)
Time
(sec)
Flowrate=
Volume/time
(ml/sec)
(cm)
1.
21
20
20.5
1000
16.04
62.34
2.
19
18
18.5
2000
32.73
61.10
3.
17
17.5
17.5
3000
51.32
58.45
Graph 2:
Slope = Resistance =R= 1.29 sec/cm2
Storage= πD2/4= 1.327 cm2
Time Constant = 1.71 seconds
3rd Run:
Length of the tube = 50 cm
Inner Diameter of tube = 1.3 cm
Page | 45
No. of
Initial level of
Final level of
Observ
the water
the water
Mean
level
Volume
(ml)
Time
(sec)
Flowrate=
Volume/time
(ml/sec)
a tions
(cm)
(cm)
(cm)
1
17
16
16.5
1000
18.18
55.00
2
16
15
15.5
2000
37.11
53.89
3
15
14
14.5
3000
57.07
52.56
Graph 3:
Slope = Resistance =R= 1.22 sec/cm2
Storage= πD2/4= 1.327 m2
Time Constant = R × Storage
Time Constant = 1.61 seconds
References:

Coach, E. (n.d.). Retrieved from https://electronicscoach.com/liquid-level-control-system.html

Instrumentation & Control Lab Manual
Page | 46
Experiment No. 6
Liquid Controller Rig
Objective:
Determination of the gain of the first order level system.
Apparatus:

Tank

Liquid level control system

Flowmeter

Portable compressor
Procedure:
1. Fill the level in the tank through bypass valve of the control valve
2. Switch on the compressor and analyze the current value of level on the controller.
3. Initially analyze the inlet flowrate of the tank through Rota meter.
4. Change the inlet flowrate by changing the opening of control valve and analyze the
variation in level.
5. The change in level provides the output change while the input change can be measure
through Rota meter.
6. The gain can be estimated by ratio of change in output and input.
7. The same procedure is repeated to get the 5-6 reading.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Observe the liquid level carefully.
Page | 47
Experiment No. 7
PLC Control (Flow Control)
Objective:
Analyze the dynamics of flow system using proportional, integral and derivative controllers in
PLC control system.
Apparatus:

PLC control system
Theory:
A programmable logic controller is a type of tiny computer that can receive data through
its inputs and send operating instructions through its outputs. Fundamentally, a PLC’s job is to
control a system’s functions using the internal logic programmed into it. Businesses around the
world use PLCs to automate their most important processes. A PLC takes in inputs, whether from
automated data capture points or from human input points such as switches or buttons. Based on
its programming, the PLC then decides whether or not to change the output. A PLC’s outputs can
control a huge variety of equipment, including motors, solenoid valves, lights, switchgear, safety
shut-offs and many others. The physical location of PLCs can vary widely from one system to
another. Usually, however, PLCs are located in the general vicinity of the systems they operate,
and they’re typically protected by a surface mount electrical box. Skip to the end if you’re
interested in seeing the electrical junction boxes that help protect PLCs.
Page | 48
PLCs largely replaced the manual relay-based control systems that were common in older
industrial facilities. Relay systems are complex and prone to failure and, in the 1960s, the inventor
Richard Morley introduced the first PLCs as an alternative. Manufacturers quickly realized the
potential of PLCs and began integrating them into their work processes. Today, PLCs are still a
fundamental element of many industrial control systems. In fact, they’re still the most used
industrial control technology worldwide. The ability to work with PLCs is a required skill for many
different professions, from the engineers designing the system to the electrical technicians
maintaining it.
Proportional-Integral-Derivative (PID) control is the most common control algorithm used
in industry and has been universally accepted in industrial control. The popularity of PID
controllers can be attributed partly to their robust performance in a wide range of operating
conditions and partly to their functional simplicity, which allows engineers to operate them in a
simple, straightforward manner. Process variable is the system parameter that needs to be
controlled. The set point is the desired or command value for the process variable.
The control design process begins by defining the performance requirements. Control
system performance is often measured by applying a step function as the set point command
variable, and then measuring the response of the process variable. Commonly, the response is
quantified by measuring defined waveform characteristics. Rise Time is the amount of time the
system takes to go from 10% to 90% of the steady-state, or final, value. Percent Overshoot is the
amount that the process variable overshoots the final value, expressed as a percentage of the final
value. Settling time is the time required for the process variable to settle to within a certain
percentage (commonly 5%) of the final value. Steady-State Error is the final difference between
the process variable and set point. Note that the exact definition of these quantities will vary in
Page | 49
industry and academia.
Proportional Response:
The proportional component depends only on the difference between the set point and the
process variable. This difference is referred to as the Error term. The proportional gain (K)
determines the ratio of output response to the error signal. For instance, if the error term has a
magnitude of 10, a proportional gain of 5 would produce a proportional response of 50. In general,
increasing the proportional gain will increase the speed of the control system response. However,
if the proportional gain is too large, the process variable will begin to oscillate. If K is increased
further, the oscillations will become larger and the system will become unstable and may even
oscillate out of control.
Integral Response:
The integral component sums the error term over time. The result is that even a small error
term will cause the integral component to increase slowly. The integral response will continually
increase over time unless the error is zero, so the effect is to drive the Steady-State error to zero.
Steady-State error is the final difference between the process variable and set point. A phenomenon
called integral windup results when integral action saturates a controller without the controller
driving the error signal toward zero.
Derivative Response:
The derivative component causes the output to decrease if the process variable is increasing
rapidly. The derivative response is proportional to the rate of change of the process variable.
Increasing the derivative time (T) parameter will cause the control system to react more strongly
to changes in the error term and will increase the speed of the overall control system response.
Most practical control systems use very small derivative time (T), because the Derivative Response
is highly sensitive to noise in the process variable signal. If the sensor feedback signal is noisy or
Page | 50
if the control loop rate is too slow, the derivative response can make the control system unstable.
Advantages of Using PLCs:
PLCs have been a standard element of industrial machinery design for many decades. What
advantages do PLCs offer that make them such a popular choice?
1. PLCs are fairly intuitive to program. Their programming languages are simple in
comparison to other industrial control systems, which makes PLCs great for businesses
that want to minimize complexity and costs.
2. PLCs are a mature technology with years of testing and analysis backing them up. It’s easy
to find robust research about many different PLC types and comprehensive tutorials for
programming and integrating them.
3. PLCs are available at a wide range of price points, including many extremely affordable
basic models that small businesses and startups often use.
4. PLCs are extremely versatile, and most PLC models are suitable for controlling a wide
variety of processes and systems.
5. PLCs are completely solid-state devices, which means they have no moving parts. That
makes them exceptionally reliable and more able to survive the challenging conditions
present in many industrial facilities.
6. PLCs have relatively few components, which makes them easier to troubleshoot and helps
reduce maintenance downtime.
7. PLCs are efficient and don’t consume very much electrical power. This helps conserve
energy and may simplify wiring considerations.
Drawbacks of Using PLCs:
No technology is perfect for every scenario, and there are some applications for which
PLCs aren’t the best choice. Let’s look at some of the most significant potential drawbacks of
using PLCs.
1. PLCs have less capacity to handle extremely complex data or large numbers of processes
that involve analog rather than discrete inputs. As manufacturing facilities become more
integrated and involved, increasing numbers of them may shift toward a distributed control
system or another alternative industrial control method.
2. PLCs from different manufacturers often use proprietary programming software. This
makes PLC programming interfaces less interoperable than they might be, especially
Page | 51
considering that their programming languages share common standards (see below).
3. PLCs, like many other types of electronic equipment, are vulnerable to electromagnetic
interference (EMI). They can also experience other kinds of common electronics
malfunctions such as corrupted memory and communication failures.
Procedure:
1. Switch on the computer system as well as PLC control system.
2. Open FLTP-Flow-PID-Control from FLTP file in Start button and then in programs.
3. Click on the open button and the open the file of topology.
4. Make connection of control system according to topology given in the figure below.
5. Adjust the valves according to the experiment.
6. Switch on the pump and observe the value of flow system in PV (process variable) and SP
(Set Point). The PV and SP are represented by Yellow and Red lines respectively.
7. Observe the initial values of PV and SP. Change SP value through Knob and analyze the
graphical response.
8. Change the P, I and D value so that margin between PV and SP can be minimized.
9. Perform 4 tests and minimize the difference between two lines of graph.
10. Take snapshot of the graphical results at each test.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Ensure proper working of PLC control system.

Carefully adjust the control system according to topology.
Page | 52
Observations and Calculations:
References:

polycase. (n.d.). Retrieved from https://www.polycase.com/about-us

Instrumentation & Control Lab Manual
Page | 53
Experiment No. 8
PLC Control (Pressure Control)
Objective:
Analyze the dynamics of pressure system using proportional, integral and derivative controllers in
PLC control system.
Apparatus:

PLC control system
Theory:
A programmable logic controller is a type of tiny computer that can receive data through
its inputs and send operating instructions through its outputs. Fundamentally, a PLC’s job is to
control a system’s functions using the internal logic programmed into it. Businesses around the
world use PLCs to automate their most important processes. A PLC takes in inputs, whether from
automated data capture points or from human input points such as switches or buttons. Based on
its programming, the PLC then decides whether or not to change the output. A PLC’s outputs can
control a huge variety of equipment, including motors, solenoid valves, lights, switchgear, safety
shut-offs and many others. The physical location of PLCs can vary widely from one system to
another. Usually, however, PLCs are located in the general vicinity of the systems they operate,
and they’re typically protected by a surface mount electrical box. Skip to the end if you’re
interested in seeing the electrical junction boxes that help protect PLCs.
Page | 54
PLCs largely replaced the manual relay-based control systems that were common in older
industrial facilities. Relay systems are complex and prone to failure and, in the 1960s, the inventor
Richard Morley introduced the first PLCs as an alternative. Manufacturers quickly realized the
potential of PLCs and began integrating them into their work processes. Today, PLCs are still a
fundamental element of many industrial control systems. In fact, they’re still the most used
industrial control technology worldwide. The ability to work with PLCs is a required skill for many
different professions, from the engineers designing the system to the electrical technicians
maintaining it.
Proportional-Integral-Derivative (PID) control is the most common control algorithm used
in industry and has been universally accepted in industrial control. The popularity of PID
controllers can be attributed partly to their robust performance in a wide range of operating
conditions and partly to their functional simplicity, which allows engineers to operate them in a
simple, straightforward manner. Process variable is the system parameter that needs to be
controlled. The set point is the desired or command value for the process variable.
The control design process begins by defining the performance requirements. Control
system performance is often measured by applying a step function as the set point command
variable, and then measuring the response of the process variable. Commonly, the response is
quantified by measuring defined waveform characteristics. Rise Time is the amount of time the
system takes to go from 10% to 90% of the steady-state, or final, value. Percent Overshoot is the
amount that the process variable overshoots the final value, expressed as a percentage of the final
value. Settling time is the time required for the process variable to settle to within a certain
percentage (commonly 5%) of the final value. Steady-State Error is the final difference between
the process variable and set point. Note that the exact definition of these quantities will vary in
Page | 55
industry and academia.
Proportional Response:
The proportional component depends only on the difference between the set point and the
process variable. This difference is referred to as the Error term. The proportional gain (K)
determines the ratio of output response to the error signal. For instance, if the error term has a
magnitude of 10, a proportional gain of 5 would produce a proportional response of 50. In general,
increasing the proportional gain will increase the speed of the control system response. However,
if the proportional gain is too large, the process variable will begin to oscillate. If K is increased
further, the oscillations will become larger and the system will become unstable and may even
oscillate out of control.
Integral Response:
The integral component sums the error term over time. The result is that even a small error
term will cause the integral component to increase slowly. The integral response will continually
increase over time unless the error is zero, so the effect is to drive the Steady-State error to zero.
Steady-State error is the final difference between the process variable and set point. A phenomenon
called integral windup results when integral action saturates a controller without the controller
driving the error signal toward zero.
Derivative Response:
The derivative component causes the output to decrease if the process variable is increasing
rapidly. The derivative response is proportional to the rate of change of the process variable.
Increasing the derivative time (T) parameter will cause the control system to react more strongly
to changes in the error term and will increase the speed of the overall control system response.
Most practical control systems use very small derivative time (T), because the Derivative Response
is highly sensitive to noise in the process variable signal. If the sensor feedback signal is noisy or
Page | 56
if the control loop rate is too slow, the derivative response can make the control system unstable.
Advantages of Using PLCs:
PLCs have been a standard element of industrial machinery design for many decades. What
advantages do PLCs offer that make them such a popular choice?
1. PLCs are fairly intuitive to program. Their programming languages are simple in
comparison to other industrial control systems, which makes PLCs great for businesses
that want to minimize complexity and costs.
2. PLCs are a mature technology with years of testing and analysis backing them up. It’s easy
to find robust research about many different PLC types and comprehensive tutorials for
programming and integrating them.
3. PLCs are available at a wide range of price points, including many extremely affordable
basic models that small businesses and startups often use.
4. PLCs are extremely versatile, and most PLC models are suitable for controlling a wide
variety of processes and systems.
5. PLCs are completely solid-state devices, which means they have no moving parts. That
makes them exceptionally reliable and more able to survive the challenging conditions
present in many industrial facilities.
6. PLCs have relatively few components, which makes them easier to troubleshoot and helps
reduce maintenance downtime.
7. PLCs are efficient and don’t consume very much electrical power. This helps conserve
energy and may simplify wiring considerations.
Drawbacks of Using PLCs:
No technology is perfect for every scenario, and there are some applications for which
PLCs aren’t the best choice. Let’s look at some of the most significant potential drawbacks of
using PLCs.
1. PLCs have less capacity to handle extremely complex data or large numbers of processes
that involve analog rather than discrete inputs. As manufacturing facilities become more
integrated and involved, increasing numbers of them may shift toward a distributed control
system or another alternative industrial control method.
2. PLCs from different manufacturers often use proprietary programming software. This
makes PLC programming interfaces less interoperable than they might be, especially
Page | 57
considering that their programming languages share common standards (see below).
3. PLCs, like many other types of electronic equipment, are vulnerable to electromagnetic
interference (EMI). They can also experience other kinds of common electronics
malfunctions such as corrupted memory and communication failures.
Procedure:
1. Switch on the computer system as well as PLC control system.
2. Open FLTP-Pressure-PID-Control from FLTP file in Start button and then in programs.
3. Click on the open button and the open the file of topology.
4. Make connection of control system according to topology given in the figure below.
5. Adjust the valves according to the experiment.
6. Switch on the pump and observe the value of flow system in PV (process variable) and SP
(Set Point). The PV and SP are represented by Yellow and Red lines respectively.
7. Observe the initial values of PV and SP. Change SP value through Knob and analyze the
graphical response.
8. Change the P, I and D value so that margin between PV and SP can be minimized.
9. Perform 4 tests and minimize the difference between two lines of graph.
10. Take snapshot of the graphical results at each test.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Ensure proper working of PLC control system.

Carefully adjust the control system according to topology.
Page | 58
Observations and Calculations:
References:

polycase. (n.d.). Retrieved from https://www.polycase.com/about-us

Instrumentation & Control Lab Manual
Page | 59
Experiment No. 9
PLC Control (Temperature Control)
Objective:
Analyze the dynamics of temperature system using proportional, integral and derivative controllers
in PLC control system.
Apparatus:

PLC control system
Theory:
A programmable logic controller is a type of tiny computer that can receive data through
its inputs and send operating instructions through its outputs. Fundamentally, a PLC’s job is to
control a system’s functions using the internal logic programmed into it. Businesses around the
world use PLCs to automate their most important processes. A PLC takes in inputs, whether from
automated data capture points or from human input points such as switches or buttons. Based on
its programming, the PLC then decides whether or not to change the output. A PLC’s outputs can
control a huge variety of equipment, including motors, solenoid valves, lights, switchgear, safety
shut-offs and many others. The physical location of PLCs can vary widely from one system to
another. Usually, however, PLCs are located in the general vicinity of the systems they operate,
and they’re typically protected by a surface mount electrical box. Skip to the end if you’re
interested in seeing the electrical junction boxes that help protect PLCs.
Page | 60
PLCs largely replaced the manual relay-based control systems that were common in older
industrial facilities. Relay systems are complex and prone to failure and, in the 1960s, the inventor
Richard Morley introduced the first PLCs as an alternative. Manufacturers quickly realized the
potential of PLCs and began integrating them into their work processes. Today, PLCs are still a
fundamental element of many industrial control systems. In fact, they’re still the most used
industrial control technology worldwide. The ability to work with PLCs is a required skill for many
different professions, from the engineers designing the system to the electrical technicians
maintaining it.
Proportional-Integral-Derivative (PID) control is the most common control algorithm used
in industry and has been universally accepted in industrial control. The popularity of PID
controllers can be attributed partly to their robust performance in a wide range of operating
conditions and partly to their functional simplicity, which allows engineers to operate them in a
simple, straightforward manner. Process variable is the system parameter that needs to be
controlled. The set point is the desired or command value for the process variable.
The control design process begins by defining the performance requirements. Control
system performance is often measured by applying a step function as the set point command
variable, and then measuring the response of the process variable. Commonly, the response is
quantified by measuring defined waveform characteristics. Rise Time is the amount of time the
system takes to go from 10% to 90% of the steady-state, or final, value. Percent Overshoot is the
amount that the process variable overshoots the final value, expressed as a percentage of the final
value. Settling time is the time required for the process variable to settle to within a certain
percentage (commonly 5%) of the final value. Steady-State Error is the final difference between
the process variable and set point. Note that the exact definition of these quantities will vary in
Page | 61
industry and academia.
Proportional Response:
The proportional component depends only on the difference between the set point and the
process variable. This difference is referred to as the Error term. The proportional gain (K)
determines the ratio of output response to the error signal. For instance, if the error term has a
magnitude of 10, a proportional gain of 5 would produce a proportional response of 50. In general,
increasing the proportional gain will increase the speed of the control system response. However,
if the proportional gain is too large, the process variable will begin to oscillate. If K is increased
further, the oscillations will become larger and the system will become unstable and may even
oscillate out of control.
Integral Response:
The integral component sums the error term over time. The result is that even a small error
term will cause the integral component to increase slowly. The integral response will continually
increase over time unless the error is zero, so the effect is to drive the Steady-State error to zero.
Steady-State error is the final difference between the process variable and set point. A phenomenon
called integral windup results when integral action saturates a controller without the controller
driving the error signal toward zero.
Derivative Response:
The derivative component causes the output to decrease if the process variable is increasing
rapidly. The derivative response is proportional to the rate of change of the process variable.
Increasing the derivative time (T) parameter will cause the control system to react more strongly
to changes in the error term and will increase the speed of the overall control system response.
Most practical control systems use very small derivative time (T), because the Derivative Response
is highly sensitive to noise in the process variable signal. If the sensor feedback signal is noisy or
Page | 62
if the control loop rate is too slow, the derivative response can make the control system unstable.
Advantages of Using PLCs:
PLCs have been a standard element of industrial machinery design for many decades. What
advantages do PLCs offer that make them such a popular choice?
1. PLCs are fairly intuitive to program. Their programming languages are simple in
comparison to other industrial control systems, which makes PLCs great for businesses
that want to minimize complexity and costs.
2. PLCs are a mature technology with years of testing and analysis backing them up. It’s easy
to find robust research about many different PLC types and comprehensive tutorials for
programming and integrating them.
3. PLCs are available at a wide range of price points, including many extremely affordable
basic models that small businesses and startups often use.
4. PLCs are extremely versatile, and most PLC models are suitable for controlling a wide
variety of processes and systems.
5. PLCs are completely solid-state devices, which means they have no moving parts. That
makes them exceptionally reliable and more able to survive the challenging conditions
present in many industrial facilities.
6. PLCs have relatively few components, which makes them easier to troubleshoot and helps
reduce maintenance downtime.
7. PLCs are efficient and don’t consume very much electrical power. This helps conserve
energy and may simplify wiring considerations.
Drawbacks of Using PLCs:
No technology is perfect for every scenario, and there are some applications for which
PLCs aren’t the best choice. Let’s look at some of the most significant potential drawbacks of
using PLCs.
1. PLCs have less capacity to handle extremely complex data or large numbers of processes
that involve analog rather than discrete inputs. As manufacturing facilities become more
integrated and involved, increasing numbers of them may shift toward a distributed control
system or another alternative industrial control method.
2. PLCs from different manufacturers often use proprietary programming software. This
makes PLC programming interfaces less interoperable than they might be, especially
Page | 63
considering that their programming languages share common standards (see below).
3. PLCs, like many other types of electronic equipment, are vulnerable to electromagnetic
interference (EMI). They can also experience other kinds of common electronics
malfunctions such as corrupted memory and communication failures.
Procedure:
1. Switch on the computer system as well as PLC control system.
2. Open FLTP-Temperature-PID-Control from FLTP file in Start button and then in
programs.
3. Click on the open button and the open the file of topology.
4. Make connection of control system according to topology given in the figure below.
5. Adjust the valves according to the experiment.
6. Switch on the pump and observe the value of flow system in PV (process variable) and SP
(Set Point). The PV and SP are represented by Yellow and Red lines respectively.
7. Observe the initial values of PV and SP. Change SP value through Knob and analyze the
graphical response.
8. Change the P, I and D value so that margin between PV and SP can be minimized.
9. Perform 4 tests and minimize the difference between two lines of graph.
10. Take snapshot of the graphical results at each test.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Ensure proper working of PLC control system.

Carefully adjust the control system according to topology.
Page | 64
Observations and Calculations:
References:

polycase. (n.d.). Retrieved from https://www.polycase.com/about-us

Instrumentation & Control Lab Manual
Page | 65
Experiment No. 10
PLC Control (Level Control)
Objective:
Analyze the dynamics of level system using proportional, integral and derivative controllers in
PLC control system.
Apparatus:

PLC control system
Theory:
A programmable logic controller is a type of tiny computer that can receive data through
its inputs and send operating instructions through its outputs. Fundamentally, a PLC’s job is to
control a system’s functions using the internal logic programmed into it. Businesses around the
world use PLCs to automate their most important processes. A PLC takes in inputs, whether from
automated data capture points or from human input points such as switches or buttons. Based on
its programming, the PLC then decides whether or not to change the output. A PLC’s outputs can
control a huge variety of equipment, including motors, solenoid valves, lights, switchgear, safety
shut-offs and many others. The physical location of PLCs can vary widely from one system to
another. Usually, however, PLCs are located in the general vicinity of the systems they operate,
and they’re typically protected by a surface mount electrical box. Skip to the end if you’re
interested in seeing the electrical junction boxes that help protect PLCs.
Page | 66
PLCs largely replaced the manual relay-based control systems that were common in older
industrial facilities. Relay systems are complex and prone to failure and, in the 1960s, the inventor
Richard Morley introduced the first PLCs as an alternative. Manufacturers quickly realized the
potential of PLCs and began integrating them into their work processes. Today, PLCs are still a
fundamental element of many industrial control systems. In fact, they’re still the most used
industrial control technology worldwide. The ability to work with PLCs is a required skill for many
different professions, from the engineers designing the system to the electrical technicians
maintaining it.
Proportional-Integral-Derivative (PID) control is the most common control algorithm used
in industry and has been universally accepted in industrial control. The popularity of PID
controllers can be attributed partly to their robust performance in a wide range of operating
conditions and partly to their functional simplicity, which allows engineers to operate them in a
simple, straightforward manner. Process variable is the system parameter that needs to be
controlled. The set point is the desired or command value for the process variable.
The control design process begins by defining the performance requirements. Control
system performance is often measured by applying a step function as the set point command
variable, and then measuring the response of the process variable. Commonly, the response is
quantified by measuring defined waveform characteristics. Rise Time is the amount of time the
system takes to go from 10% to 90% of the steady-state, or final, value. Percent Overshoot is the
amount that the process variable overshoots the final value, expressed as a percentage of the final
value. Settling time is the time required for the process variable to settle to within a certain
percentage (commonly 5%) of the final value. Steady-State Error is the final difference between
the process variable and set point. Note that the exact definition of these quantities will vary in
Page | 67
industry and academia.
Proportional Response:
The proportional component depends only on the difference between the set point and the
process variable. This difference is referred to as the Error term. The proportional gain (K)
determines the ratio of output response to the error signal. For instance, if the error term has a
magnitude of 10, a proportional gain of 5 would produce a proportional response of 50. In general,
increasing the proportional gain will increase the speed of the control system response. However,
if the proportional gain is too large, the process variable will begin to oscillate. If K is increased
further, the oscillations will become larger and the system will become unstable and may even
oscillate out of control.
Integral Response:
The integral component sums the error term over time. The result is that even a small error
term will cause the integral component to increase slowly. The integral response will continually
increase over time unless the error is zero, so the effect is to drive the Steady-State error to zero.
Steady-State error is the final difference between the process variable and set point. A phenomenon
called integral windup results when integral action saturates a controller without the controller
driving the error signal toward zero.
Derivative Response:
The derivative component causes the output to decrease if the process variable is increasing
rapidly. The derivative response is proportional to the rate of change of the process variable.
Increasing the derivative time (T) parameter will cause the control system to react more strongly
to changes in the error term and will increase the speed of the overall control system response.
Most practical control systems use very small derivative time (T), because the Derivative Response
is highly sensitive to noise in the process variable signal. If the sensor feedback signal is noisy or
Page | 68
if the control loop rate is too slow, the derivative response can make the control system unstable.
Advantages of Using PLCs:
PLCs have been a standard element of industrial machinery design for many decades. What
advantages do PLCs offer that make them such a popular choice?
1. PLCs are fairly intuitive to program. Their programming languages are simple in
comparison to other industrial control systems, which makes PLCs great for businesses
that want to minimize complexity and costs.
2. PLCs are a mature technology with years of testing and analysis backing them up. It’s
easy to find robust research about many different PLC types and comprehensive tutorials
for programming and integrating them.
3. PLCs are available at a wide range of price points, including many extremely affordable
basic models that small businesses and startups often use.
4. PLCs are extremely versatile, and most PLC models are suitable for controlling a wide
variety of processes and systems.
5. PLCs are completely solid-state devices, which means they have no moving parts. That
makes them exceptionally reliable and more able to survive the challenging conditions
present in many industrial facilities.
6. PLCs have relatively few components, which makes them easier to troubleshoot and
helps reduce maintenance downtime.
7. PLCs are efficient and don’t consume very much electrical power. This helps conserve
energy and may simplify wiring considerations.
Drawbacks of Using PLCs:
No technology is perfect for every scenario, and there are some applications for which
PLCs aren’t the best choice. Let’s look at some of the most significant potential drawbacks of
using PLCs.
1. PLCs have less capacity to handle extremely complex data or large numbers of processes
that involve analog rather than discrete inputs. As manufacturing facilities become more
integrated and involved, increasing numbers of them may shift toward a distributed
control system or another alternative industrial control method.
2. PLCs from different manufacturers often use proprietary programming software. This
makes PLC programming interfaces less interoperable than they might be, especially
Page | 69
considering that their programming languages share common standards (see below).
3. PLCs, like many other types of electronic equipment, are vulnerable to electromagnetic
interference (EMI). They can also experience other kinds of common electronics
malfunctions such as corrupted memory and communication failures.
Procedure:
1. Switch on the computer system as well as PLC control system.
2. Open FLTP-Level-PID-Control from FLTP file in Start button and then in programs.
3. Click on the open button and the open the file of topology.
4. Make connection of control system according to topology given in the figure below.
5. Adjust the valves according to the experiment.
6. Switch on the pump and observe the value of flow system in PV (process variable) and SP
(Set Point). The PV and SP are represented by Yellow and Red lines respectively.
7. Observe the initial values of PV and SP. Change SP value through Knob and analyze the
graphical response.
8. Change the P, I and D value so that margin between PV and SP can be minimized.
9. Perform 4 tests and minimize the difference between two lines of graph.
10. Take snapshot of the graphical results at each test.
Safety Precautions:

Wear lab coats and closed shoes in laboratory premises

Ensure proper working of PLC control system.

Carefully adjust the control system according to topology.
Page | 70
Observations and Calculations:
References:

polycase. (n.d.). Retrieved from https://www.polycase.com/about-us

Instrumentation & Control Lab Manual
Page | 71
Experiment No. 11
Thermocouple K-type (Open Ended)
Abstract:
A thermocouple consists of two wires of two different materials that are joined at each end.
When these two junctions are kept at different temperatures a small electric current is induced.
Due to the flow of current a voltage drop occurs. This voltage drop depends on the temperature
difference between the two junctions. The measurement of the voltage drop can then be correlated
to this temperature difference. It is extremely important to note that a thermocouple does not
measure the temperature, but rather the temperature difference between the two junctions. In order
to use a thermocouple to measure temperature directly, one junction must be maintained at a known
temperature. This junction is commonly called the reference junction (which is kept at 0℃ usually)
and its temperature is the reference temperature. The other junction, which is normally placed in
contact with the body of unknown temperature, is called the measurement junction. Time constant
𝜏 is the time taken by the response function to register 63.2% of its ultimate value is called time
constant.
Page | 72
Objective:
Determination of the time constant of the given thermocouple (K-type) and also find out
the response “Tb” of the system when t=τ, t=2τ, t=3τ.
Apparatus:

Thermocouple

Heater

Digital Voltmeter

Stop watch

Hookup wires
Reagents:
1. Diesel Oil
2. Kerosene Oil
3. Coconut Oil
Theory:
Introduction:
Type K Thermocouple provides widest operating temperature range. It consist of positive
leg which is non-magnetic and negative leg which is magnetic. In K Type Thermocouple
traditional base metal is used due to which it can work at high temperature and can provide widest
operating temperature range. One of the constituent metal in K Type Thermocouple is Nickel,
which is magnetic in nature.
The characteristic shown by K Type Thermocouple is that they undergo a deviation in
output when magnetic material reaches its Curie point, at around 185 °C. K
Page | 73
Type thermocouple work very well in oxidizing atmosphere at temperatures up to 1260°C
(2300°F) and its tolerance class is ± 1.5 K between -40 and 375 °C. (Instruments, 1976).
Why to prefer K Type Thermocouple?
1. One of the major advantage of K type thermocouple over other thermocouple's is it can
function in rugged environmental condition & in various atmosphere.
2. It has integrated composition of Chromel and Alumel wires has a range of -270 °C to
1260°C and an output of -6.4 to 9 mV over maximum temperature range.
3. Also known as general purpose thermocouple due to its wide range of temperature.
4. Type K has a longer life than Type J as in Type J Fe (iron) wire oxidizes rapidly, especially
at higher temperature.
5. They are inexpensive.
6. Have a fast response.
7. Small in size and are reliable.
8. Generally used at temperatures above 540 degrees C.
Composition of K Type Thermocouple:
In K Type Thermocouple positive leg is composed of 90% nickel, 10%chromium and a
negative leg is composed of 95% nickel, 2% aluminum, 2% manganese and 1% silicon. These are
the most common general purpose thermocouple with a sensitivity of approx. 41µV/°C.
(Instruments, 1976).
Type K Insulation Material:
In Type K Thermocouple mainly two type of insulation is used firstly Ceramic beads
insulation is used as it is a lightweight insulating product. It is made from high purity aluminosilicate materials. It has low thermal mass which means that it does not retain heat, low thermal
conductivity and is an extremely effective insulation material as it can withstand
high temperature of 1260 °C so it it best suited material for Type K thermocouple. (Instruments,
Page | 74
1976).
Secondly compacted mineral insulation and outer metal sheath (MgO) is used. Magnesium
Oxide has a high dielectric strength, responds quickly to temperature changes and is very durable.
It has typical Composition of the Standard Quality MgO (97%) and the High Purity MgO and
AI2O3. (Instruments, 1976).
Magnesium Oxide insulation is recommended for K Type thermocouple when
Thermocouple are to be immersed in liquids, high moisture, corrosive gases or high pressures. The
thermocouple can be formed to reach otherwise inaccessible areas. (Instruments, 1976).
Temperature Range:
To find appropriate range of thermocouple we should use appropriate wire because
different wires measure various temperature ranges. Of the four major thermocouple types, type
K covers the widest range:
Thermocouple grade wire, –454 to 2,300F (–270 to1260°C)

Extension wire, 32 to 392F (0 to200°C)
Accuracy (whichever is greater):

Standard: +/- 2.2°C or +/-.75%

Special Limits of Error: +/- l°C or0.4%
Page | 75
Tolerance Class:
EMF Vs Temperature Graph for K Type Thermocouple:
Pros and Cons:
Pros:
1. To measure temperature it provide good linearity of emf.
2. It provide good resistance aganist oxidation below 1000 °C (1600°F).
3. Highly stable output.
4. Comparatively cost effective than other thermocouple.
Cons:
1. Not suitable for reducing atmosphere but can withstand metallic.
2. Aging of the emf characteristic, when compared to noble metal thermocouples (B, R, and
S).
3. Not suitable for vacuum applications due to vaporization of chromium in the positive
element.
4. Green-Rotis phenomenon may occur due to low oxygen level for the thermocouples which
are used between 815°C to 1040°C (1500°F to1900°F).
5. Type K thermocouples should not be used in Sulphuric environment since both elements
will rapidly corrode and the negative element will eventually fail mechanically due to
becoming brittle.
Page | 76
Uses of K Type Thermocouple:
They are mostly used for applications at temperatures above 550 °C up to the maximum
working pressure of the thermocouple.
1. They are used in many industries like Steel & Iron to monitor temperature & chemistry
throughout the steel making process.
2. Used for testing temperatures associated with process plants e.g. chemical production and
petroleum refineries.
3. Used for Testing of heating appliance safety.
4. Type K is commonly used in nuclear applications because of its relative radiation hardness.
Procedure:
1. Position the Stand (without the thermocouple) on a table top and ensure that the base is
horizontal by using the spirit level.
2. Inert the thermocouple in the stand so that it can move easily.
3. Place the heater adjacent to the stand and ensure proper electrical supply to the heater.
4. Connect the wires of Voltmeter to the corresponding wires of thermocouple. After this, the
apparatus is ready to perform the experiment.
5. Ensure that circuit is complete as shown in schematic diagram using Digital Voltmeter.
6. Note the reading on digital voltmeter.
7. Switch on the heater. As thermocouple receives heat, digital voltmeter reading changes.
8. The ultimate value of temperature has been considered 200oC for this experiment.
9. The conversion chart of voltage to temperature for the K type thermocouple is given below.
10. The measuring junction of thermocouple to be heated till the voltage appears on volt meter
to
the range of (5.328 to 5.735) and measure the time duration by stopwatch to reach this
voltage
level for estimating the response time. It is the estimation of response time at t=τ.
11. Repeat this procedure for the remaining values of time constants and plot a graph as
mentioned below.
Safety Precautions:
1. Wear lab coats and closed shoes in laboratory premises.
2. Ensure proper working of miniature circuit breakers (MCB).
Page | 77
3. Carefully insert the thermocouple in the stand.
4. Immediately switch off the heater if there is any spark in heater’s power plug.
Observations & Calculations:
Room Temperature = Ts = 37 oC
Ultimate value of temperature = T = 160 oC
Amplitude = A = T – Ts = 160 – 37 = 123 oC
For Diesel Oil:
No. of
Observations
Time (t)
sec
Thermocouple
Readings (Tb)
oC
Tb-Ts = Tb*
oC
Respond of
a system
Tb*/A
Response Time
-ln (1- (Tb* /
A))
= t/ τb
1.
20
40
3
0.02439
0.0246
2.
15
50
13
0.10569
0.1117
3.
10
60
23
0.18699
0.2070
Thermocouple
Readings (Tb)
oC
Tb-Ts = Tb*
oC
Respond of
a system
Tb*/A
Response Time
-ln (1- (Tb* /
A))
= t/ τb
For Kerosene Oil:
No. of
Time (t)
Observations
sec
1.
30
25
-12
-0.09756
0.09400
2.
20
35
-2
-0.01626
0.016129
3.
10
45
8
0.06504
0.067251
Page | 78
For Coconut Oil:
No. of
Time (t)
Observations
sec
Thermocouple
Readings (Tb)
oC
Tb-Ts = Tb*
oC
Respond of
a system
Tb*/A
Response Time
-ln (1- (Tb* /
A))
= t/ τb
1.
70
60
23
0.18699
0.20701
2.
50
85
48
0.39024
0.494689
3.
30
100
63
0.51219
0.717829
Graphs:
Figure
(Diesel Oil)
Page | 79
Figure (Diesel Oil)
Figure (Kerosene Oil)
Page | 80
Figure (Coconut Oil)
Figure (Coconut Oil)
Discussion:
The type K is the most common type of thermocouple. It’s inexpensive, accurate, reliable, and
has a wide temperature range. After getting the data and graph we could possibly said that the when the
increase in the time occur than the temperature also increase and same in the case of the response time and
Page | 81
response.
Conclusion:
One of the major advantage of K type thermocouple over other thermocouple's is it can
functions in rugged environmental condition & in various atmosphere. It has integrated
composition of Chromel and Alumel wires has a range of -270 °C to 1260°C and an output of 6.4 to 9 mV over maximum temperature range. Also known as general purpose thermocouple due
to its wide range of temperature. Type K has a longer life than Type J as in Type J Fe (iron) wire
oxidizes rapidly, especially at higher temperature. They are inexpensive. It have a fast response. It
is small in size and are reliable. Generally used at temperatures above 540 degrees C.
Reference:

Instruments, T. (1976). K Type Thermocouple. Retrieved from Tempsens Instruments:
https://tempsens.com/blog/k-type-thermocouple#

Lab Manual of Instrumentation & Control lab
Page | 82
Experiment No. 12
Instrumentation & Control on Mass Transfer Lab
Equipment No: 01
Gas/liquid Absorption Column
Diagram:
Instrumentation & Control:
1. Level Indicator
2. Valves
3. Flow Indicator(Rotameter)
4. Regulator
5. CO2 Flow meter
Description:
Level Indicator:
Page | 83
Level indicators are devices used in the measurement of level of fluids at various industrial
applications. These devices are used to determine the level of liquid in tanks, drums. Pressure
vessels etc.
Apart from glass tube level gauges, transparent level gauges are always fitted with two
plate transparent glasses between which the fluid is contained. The fluid level is indicated as the
result of the different transparency of the two media and in some cases (for water steam), by
conveying upwards on to the surface of separation (between liquid and gaseous substances) a
source of light located at the back of the gauge, the rays of which are totally reflected down to the
observer.
Ball Valves:
Ball valves are a common type of valve in life and are mainly used for fluid regulation and
control. According to the working conditions, ball valves can be equipped with different driving
devices to form a variety of different control methods, such as electric ball valves, pneumatic ball
valves, hydraulic ball valves, and the like.
The Ball valve uses a hollow, perforated and pivoting ball to control flow through it. The
ball valve drives the valve handle to rotate by a transmission, which in turn drives the ball to rotate
about an axis perpendicular to the flow. It is open when the ball’s hole is in line with the flow and
closed when it is pivoted 90-degrees by the valve handle.
Flow Indicator (Rotameter):
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
Page | 84
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Regulator:
A voltage regulator is designed to automatically ‘regulate’ voltage level. It basically steps
down the input voltage to the desired level and keeps that in that same level during the supply.
This makes sure that even when a load is applied the voltage doesn’t drop.
Thus, a voltage regulator is used for two reasons:
To regulate or vary the output voltage of the circuit.

To keep the output voltage constant at the desired value in-spite of variations in the supply
voltage or in the load current.
CO2 Flow meter:
Thermal mass flow meters are precision instruments that measure gas mass flow. The
device is used in a wide range of applications in many industries. Thermal mass flow meters are
used almost entirely for gas flow applications. As the name implies, the meters use heat to measure
flow, and they introduce heat into a flowing stream and measure how much heat dissipates using
one or more temperature sensors. This method works best with gas mass flow measurement. Due
to heat absorption considerations, it is challenging to get a strong signal using thermal mass flow
meters in liquids.
Equipment No: 02
Distillation Column
Diagram:
Page | 85
Instrumentation & Control:
1. Pressure Gauge
2. Thermocouple
3. Level Indicator
4. Flow meter
5. Temperature Controller
6. Temperature Sensor
7. Valve
Description:
Pressure Gauge:
A pressure gauge is a measuring instrument used to measure the level of pressure in a liquid
or gas, across industries. It is a crucial instrument as it also helps control the levels of pressure in
liquids and gases and keep them in the required limit. It raises an alarm in case the pressure
exceeds.
The working principle of pressure gauges is based on Hooke’s law, which states that the
force required to expand or compress a spring scales in a linear manner with regards to the distance
of extension or compression. There is inner pressure and outer pressure. So, when pressure is
applied on the surface of the object, it is more on the inner side as the pressure area is less. Bourdon
pressure gauges are widely used across industries, and they work on this principle.
Digital pressure gauges are nowadays commonly used. In case of digital pressure gauges,
the AC and DC power supplies play a major role. The switching circuit or AC is converted to DC.
The measured pressure is transmitted to the sensor diaphragm which senses the pressure, based on
which an electrical signal is generated to reach to the computer or smartphone. These gauges come
with a small LCD display.
Thermocouple:
A thermocouple is made up of two dissimilar metals, joined together at one end, that
produce a voltage (expressed in millivolts) with a change in temperature. The junction of the two
metals, called the sensing junction, is connected to extension wires. Any two dissimilar metals
may be used to make a thermocouple.
When two dissimilar metals are connected together, a small voltage called a thermojunction voltage is generated at the junction. This is called the Peltier effect.
Page | 86
If the temperature of the junction changes, it causes voltage to change too, which can be
measured by the input circuits of an electronic controller. The output is a voltage proportional to
the temperature difference between the junction and the free ends. This is called the Thompson
effect.
Both of these effects can be combined to measure temperature. By holding one junction at
a known temperature (reference junction) and measuring the voltage, the temperature at the
sensing junction can be deduced. The voltage generated is directly proportional to the temperature
difference. The combined effect is known as the thermo-junction effect or the See beck effect.
Level Indicator:
Level indicators are devices used in the measurement of level of fluids at various
industrial applications. These devices are used to determine the level of liquid in tanks, drums.
Pressure vessels etc.
Apart from glass tube level gauges, transparent level gauges are always fitted with two
plate transparent glasses between which the fluid is contained. The fluid level is indicated as the
result of the different transparency of the two media and in some cases (for water steam), by
conveying upwards on to the surface of separation (between liquid and gaseous substances) a
source of light located at the back of the gauge, the rays of which are totally reflected down to the
observer.
Flow meter:
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
Page | 87
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Temperature Controller:
A temperature controller is an instrument used to control temperature calculating the
difference between a set point and a measured temperature. The controller takes an input from a
temperature sensor and has an output that is connected to a control element such as a heater or fan.
To accurately control process temperature without extensive operator involvement, a
temperature control system relies upon a controller, which accepts a temperature sensor such as
a thermocouple or RTD as input. It compares the actual temperature to the desired control
temperature, or set point, and provides an output to a control element. The temperature controller
or thermostat is one part of the entire control system, and the whole system should be analyzed in
selecting the proper equipment.
Gate Valve:
A gate valve functions by lifting a rectangular or circular gate out of the path of the fluid.
When the valve is fully open, gate valves are full bore, meaning there is nothing to obstruct the
flow because the gate and pipeline diameter have the same opening. This bore diameter also
determines the valve size. An advantage of this full bore design is very low friction loss, which
saves energy and reduces total cost of ownership.
Equipment No: 03
Liquid-Liquid Extraction
Diagram:
Page | 88
Instrumentation & Control:
1. Rotameter
2. Level Indicator
Description:
Rotameter:
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Level Indicator:
Level indicators are devices used in the measurement of level of fluids at various
industrial applications. These devices are used to determine the level of liquid in tanks, drums.
Pressure vessels etc.
Apart from glass tube level gauges, transparent level gauges are always fitted with two
plate transparent glasses between which the fluid is contained. The fluid level is indicated as the
result of the different transparency of the two media and in some cases (for water steam), by
conveying upwards on to the surface of separation (between liquid and gaseous substances) a
source of light located at the back of the gauge, the rays of which are totally reflected down to the
observer.
Equipment No: 04
Wetted wall Column
Page | 89
Diagram:
Instrumentation & Control:
1. Rotameter
2. Level Indicator
3. Gate Valve
4. Control Unit
5. Temperature sensor
6. Current Sensor
Description:
Rotameter:
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
Page | 90
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Level Indicator:
Level indicators are devices used in the measurement of level of fluids at various
industrial applications. These devices are used to determine the level of liquid in tanks, drums.
Pressure vessels etc.
Apart from glass tube level gauges, transparent level gauges are always fitted with two
plate transparent glasses between which the fluid is contained. The fluid level is indicated as the
result of the different transparency of the two media and in some cases (for water steam), by
conveying upwards on to the surface of separation (between liquid and gaseous substances) a
source of light located at the back of the gauge, the rays of which are totally reflected down to the
observer.
Gate Valve:
A gate valve functions by lifting a rectangular or circular gate out of the path of the fluid.
When the valve is fully open, gate valves are full bore, meaning there is nothing to obstruct the
flow because the gate and pipeline diameter have the same opening. This bore diameter also
determines the valve size. An advantage of this full bore design is very low friction loss, which
saves energy and reduces total cost of ownership.
Control Unit:
A control unit or CU is circuitry that directs operations within a computer's processor. It
lets the computer's logic unit, memory, and both input and output devices know how to respond to
instructions received from a program. Examples of devices that utilize control units
include CPUs and GPUs.
A control unit works by receiving input information that it converts into control signals,
which are then sent to the central processor. The computer's processor then tells the
attached hardware what operations to carry out. The functions that a control unit performs are
dependent on the type of CPU, due to the variance of architecture between different manufacturers.
Page | 91
The following diagram illustrates how instructions from a program are processed.
Temperature sensor:
Temperature sensors are a simple instrument that measures the degree of hotness or
coolness and converts it into a readable unit. But, have you ever wondered how the temperature of
the soil, boreholes, huge concrete dams or buildings is measured? Well, this is accomplished
through some of the specialized temperature sensors.
The basic principle of working of the temperature sensors is the voltage across the diode
terminals. If the voltage increases, the temperature also rises, followed by a voltage drop between
the transistor terminals of base and emitter in a diode.
Current Sensor:
Current sensors, also commonly referred to as current transformers or CTs, are devices that
measure the current running through a wire by using the magnetic field to detect the current and
generate a proportional output. They are used with both AC and DC current. Current sensors allow
us to be able to measure current passively, without interrupting the circuit in any way. They are
placed around the conductor that’s current we want to measure. When current flows through a
conductor, it creates a proportional magnetic field around the conductor. Current transformers use
this magnetic field to measure current flow.
Equipment No: 05
Rotary Drum
Diagram:
Instrumentation & Control:
1. Temperature Sensor
Page | 92
2. Temperature Control
Description:
Temperature Controller:
A temperature controller is an instrument used to control temperature calculating the difference between a
set point and a measured temperature. The controller takes an input from a temperature sensor and has
an
output
that
is
connected
to
a
control
element
such
as
a heater or
fan.
To accurately control process temperature without extensive operator involvement, a temperature
control
system
relies
upon
a
controller,
which
accepts
a
temperature
sensor
such
as
a thermocouple or RTD as input. It compares the actual temperature to the desired control temperature,
or set point, and provides an output to a control element. The temperature controller or thermostat is one
part of the entire control system, and the whole system should be analyzed in selecting the proper
equipment.
Temperature sensor:
Temperature sensors are a simple instrument that measures the degree of hotness or
coolness and converts it into a readable unit. But, have you ever wondered how the temperature of
the soil, boreholes, huge concrete dams or buildings is measured? Well, this is accomplished
through some of the specialized temperature sensors.
The basic principle of working of the temperature sensors is the voltage across the diode
terminals. If the voltage increases, the temperature also rises, followed by a voltage drop between
the transistor terminals of base and emitter in a diode.
Equipment No: 06
Ion Exchanger
Diagram:
Page | 93
Instrumentation & Control:
1. Control Unit
2. Rotameter
3. Level Indicator
4. Valve
5. Temperature Sensor
Description:
Rotameter:
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Level Indicator:
Level indicators are devices used in the measurement of level of fluids at various
industrial applications. These devices are used to determine the level of liquid in tanks, drums.
Pressure vessels etc.
Apart from glass tube level gauges, transparent level gauges are always fitted with two
plate transparent glasses between which the fluid is contained. The fluid level is indicated as the
result of the different transparency of the two media and in some cases (for water steam), by
conveying upwards on to the surface of separation (between liquid and gaseous substances) a
source of light located at the back of the gauge, the rays of which are totally reflected down to the
Page | 94
observer.
Gate Valve:
A gate valve functions by lifting a rectangular or circular gate out of the path of the fluid.
When the valve is fully open, gate valves are full bore, meaning there is nothing to obstruct the
flow because the gate and pipeline diameter have the same opening. This bore diameter also
determines the valve size. An advantage of this full bore design is very low friction loss, which
saves energy and reduces total cost of ownership.
Control Unit:
A control unit or CU is circuitry that directs operations within a computer's processor. It
lets the computer's logic unit, memory, and both input and output devices know how to respond to
instructions received from a program. Examples of devices that utilize control units
include CPUs and GPUs.
A control unit works by receiving input information that it converts into control signals,
which are then sent to the central processor. The computer's processor then tells the
attached hardware what operations to carry out. The functions that a control unit performs are
dependent on the type of CPU, due to the variance of architecture between different manufacturers.
The following diagram illustrates how instructions from a program are processed.
Temperature sensor:
Temperature sensors are a simple instrument that measures the degree of hotness or
coolness and converts it into a readable unit. But, have you ever wondered how the temperature of
the soil, boreholes, huge concrete dams or buildings is measured? Well, this is accomplished
through some of the specialized temperature sensors.
The basic principle of working of the temperature sensors is the voltage across the diode
terminals. If the voltage increases, the temperature also rises, followed by a voltage drop between
the transistor terminals of base and emitter in a diode.
Equipment No: 07
Solid-Liquid Extraction
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Diagram:
Instrumentation & Control:
1. Temperature Sensor
2. Valve
3. Conductivity Sensor
Description:
Temperature sensor:
Temperature sensors are a simple instrument that measures the degree of hotness or coolness and
converts it into a readable unit. But, have you ever wondered how the temperature of the soil, boreholes,
huge concrete dams or buildings is measured? Well, this is accomplished through some of the specialized
temperature sensors.
The basic principle of working of the temperature sensors is the voltage across the diode terminals.
If the voltage increases, the temperature also rises, followed by a voltage drop between the transistor
terminals of base and emitter in a diode.
Gate Valve:
A gate valve functions by lifting a rectangular or circular gate out of the path of the fluid.
When the valve is fully open, gate valves are full bore, meaning there is nothing to obstruct the
flow because the gate and pipeline diameter have the same opening. This bore diameter also
determines the valve size. An advantage of this full bore design is very low friction loss, which
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saves energy and reduces total cost of ownership.
Conductivity Sensor:
Conductivity is the measure of a solution's ability to pass or carry an electric current. The
term Conductivity is derived from Ohm's Law, E=I•R; where Voltage (E) is the product of Current
(I) and Resistance (R); Resistance is determined by Voltage/Current. When a voltage is connected
across a conductor, a current will flow, which is dependent on the resistance of the
conductor. Conductivity is simply defined as the reciprocal of the Resistance of a solution
between two electrodes. The conductivity sensor is widely used in various water and
manufacturing process applications. A wide variety of mountings are available including screw-in
type, flange type, flow-through type, and screw-in type with gate valve.
Equipment No: 08
Aeration Unit
Diagram:
Instrumentation & Control:
1. Flowmeter
2. Temperature Sensor
3. Oxygen Indicator
Description:
Temperature sensor:
Temperature sensors are a simple instrument that measures the degree of hotness or coolness and
converts it into a readable unit. But, have you ever wondered how the temperature of the soil, boreholes,
huge concrete dams or buildings is measured? Well, this is accomplished through some of the specialized
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temperature sensors.
The basic principle of working of the temperature sensors is the voltage across the diode terminals.
If the voltage increases, the temperature also rises, followed by a voltage drop between the transistor
terminals of base and emitter in a diode.
Rotameter:
A Rotameter is a form of variable area flow meter which has a simplistic operation
whereby a liquid or gas passes through a tapered tube. In order for this gas to pass through the tube
it must first raise a float held within the tube.
When a rotameter is used with a liquid the float rises because of a combination of the
velocity head of the fluid and the buoyancy of the liquid. With a gas the buoyancy is negligible
and the float moves in the most part due to the velocity head the gas. In both cases, the greater the
flow then the higher up the tube the float moves. The float moves up and down the tapered tube in
proportion to the flow rate and the annular area between the float and the tapered tube wall. As the
float moves up through the tube because of its tapered nature the annular opening increases. As
this increases the differential pressure across the float decreases. The float stabilizes when the
weight of the float is in equilibrium with the upward force being exerted by the fluid or gas. The
float can then be compared to a calibrated scale either printed onto the tube itself or placed next to
the tube on the outside of the flow meter. The calibrated scale will commonly give a volumetric
flow reading, for example liters per minute (LPM).
Oxygen Indicator:
An oxygen sensor is one type of sensor and it is available in the exhaust system of an
automobile. The size and shape of this sensor look like a spark plug. Based on its arrangement in
regard to the catalytic converter, this sensor can be arranged before (upstream) or after
(downstream) the converter. Most of the automobiles which are designed after 1990 include
upstream & downstream O2 sensors.
The oxygen sensors used in automobiles are one sensor is arranged in front of the catalytic
converter & one is arranged in every exhaust manifold of the automobile. But, the maximum
number of these sensors in a car mainly depends on the engine, model, and year. But, most of the
vehicles have 4-sensors
The working principle of the O2 sensor is to check the oxygen amount within the exhaust.
Firstly, this oxygen was added to the fuel for good ignition. The communication of this sensor can
be done with the help of a voltage signal. So the oxygen status in the exhaust will be decided by
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the computer of the car. The computer regulates the mixture of fuel or oxygen delivered to the car
engine. The arrangement of the sensor before & after the catalytic converter permits to maintain
the hygiene of the exhaust & check the converter’s efficiency.
References:
1. (n.d.). Retrieved from computerhope: https://www.computerhope.com/jargon/c/contunit.htm
2. (n.d.). Retrieved from Encardio Rite: https://www.encardio.com/blog/temperature-sensor-probetypes-how-it-works-applications/
3. (n.d.). Retrieved from Aim Dynamics: https://aimdynamics.com/everything-about-currentsensors/
4. (n.d.). Retrieved from Yokogawa: https://www.yokogawa.com/solutions/productsplatforms/process-analyzers/liquid-analyzers/conductivity-sensors/#Overview
5. (n.d.). Retrieved from Elprocus: https://www.elprocus.com/oxygen-sensor-working-andapplications/
6. (n.d.). Retrieved from Insta tool: https://instrumentationtools.com/level-indicators-workingprinciple/
7. (n.d.). Retrieved from Adamant-Valves: http://www.adamant-valves.com/blog/what-are-ballvalves-working-principle-advantages-and-precautions-for-use/
8. (n.d.). Retrieved from Pct Flow: https://www.pctflow.com/applications/how-does-a-rotameterwork/
9. (n.d.). Retrieved from CircuitS Today: https://www.circuitstoday.com/voltage-regulators
10. (n.d.). Retrieved from SAGE: https://sagemetering.com/back-to-basics/thermal-mass-flow-meterworking-principle-and-theory/
11. (n.d.). Retrieved from Cannonwater: https://cannonwater.com/blog/pressure-gauge-how-does-itwork/
12. Instruments, T. (1976). K Type Thermocouple. Retrieved from Tempsens Instruments:
https://tempsens.com/blog/k-type-thermocouple#
13. OMEGA. (n.d.). Retrieved from https://www.omega.co.uk/prodinfo/temperature-controllers.html
14. polycase. (n.d.). Retrieved from https://www.polycase.com/about-us
15. Schlumberger. (n.d.). Retrieved from https://www.slb.com/resource-library/article/valveinsights/how-it-works-gate-valves
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