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Lecture 1

Instructor: Dr Alina Mirza
Text Books
Fundamentals of Instrumentation by U. A. Bakshi, A. V Bakshi & K.
A. Bakshi
Introduction to Instrumentation, Sensors & Process Control by
William C. Dunn
Measurement and Instrumentation Principles, by Alan S. Morris
Reference Book
Instrumentation, Measurement and Analysis by Nakra, Chaudhary
Principles of Electronic Instrumentation and Measurement by
Berlin & Getz.
Dr Alina Mirza, Dept of EE MCS, NUST
Credit Hours : 2+1
Final Exam
Assignments / Project
Dr Alina Mirza, Dept of EE MCS, NUST
Project/ assignment will be given in groups of three.
List of Groups to be provided by class senior WITHIN this week.
Groups once formed will and cannot be changed till the end of semester.
Plagiarism/copying will result in ZERO credit of either end.
20% deduction for any assignment submitted after the due date.
Missed quizzes will NOT be taken on a latter date, you will be awarded zero credit
for an on purpose missed quiz.
You may be awarded average marks /re-quized once only, based on the following
Exceptions for missing the quiz:
▪ Intimate me prior to the quiz if you need to be somewhere/ or will not be able
to attend the quiz.
▪ You must have a valid reason for missing the quiz e.g. death of a nearby
relative or on duty if intimidated by the dept.
Dr Alina Mirza, Dept of EE MCS, NUST
Attendance will only be marked if you are present in
the class.
 Absence from the class whether due to any emergency
or due to official duty will still be marked as absent.
 Neither the class senior nor any one else may ask the
instructor to mark an absent student as present.
 25% leverage on attendance is given to all students
which may be utilized for all problems that the
students face.
Dr Alina Mirza, Dept of EE MCS, NUST
▪ Office hours
▪ Contact:
10:00 am-12:00pm Every Thur
Lectures, announcements, and other related material will be
intimated through LMS or email to the class senior.
 Cell phone: only given to class senior for class correspondence ,
the instructor is not obliged to cater for any personal issues.
Attendance / Marks cases to be discussed only in the office, well
before time. Last week cases will not be considered.
Dr Alina Mirza, Dept of EE MCS, NUST
Measurement Basics and
Introduction, Advantages of Measurement, Units, Standards, Dimensions, Unit conversions, Prefixes,
Physical Constants, Significant Figures, Examples, Common Electrical Units with derivations
Instrumentation Basics,
Classification and Characteristics
Classification of Instruments, Functional Elements of an Instrumentation System, Performance
Characteristics (Calibration), Static Characteristics (Accuracy, Precision …), Dynamic Characteristics
(Response, Lag,…)
Errors in Measurement System and Types of Errors, Methods of Measurement, Loading effect
Loading effect
Basic DC Electrical Instruments
and their Measurements
Measurement of Basic Physical Quantities(Current, Voltage, Power) Basic DC Ammeter , Multi range
Ammeter , Basic DC voltmeter , Multi range Voltmeter, DC Resistance, Meter Calibration , Basic
Dynamometer ,Basic Wattmeter
Basic AC Electrical Instruments
and their Measurements
Half Wave Rectifiers, Full Wave Rectifiers, AC Voltmeters, Meter Correction
Other Quantities Measurement
Capacitance Measurement Instrument, Inductance Measurement Instrument, Frequency and Phase
Measurement Instrument
Bridge Circuits
AC, DC, Resistance , Capacitance, Inductance etc
Types, CRO …
Measurement of Physical
Temperature, Pressure, Flow, Motion, Level, Miscellaneous quantities
Quantities and Sensor Instruments
Dr Alina Mirza, Dept of EE MCS, NUST
What is Measurement?
“Measurement means to monitor a process or an
operation and using an instrument, express the
parameter, quantity or variable in terms of
meaningful numbers.”
 “Measurement provides a means of expressing a
natural phenomena or various processes in
quantitative terms.”
 Measuring instrument is a “device for
determining the value or magnitude of a
quantity or variable.”
Dr Alina Mirza, Dept of EE MCS, NUST
Most of quantities can be converted by
transducers into the electrical or electronic
An electrical signal can be amplified, filtered,
multiplexed, sampled and measured.
The measurement obtained can be converted
into digital form for automatic analysis and
Dr Alina Mirza, Dept of EE MCS, NUST
For any measurement, a well defined set of
standards and units is essential
A small number of physical quantities
selected arbitrarily are called fundamental
All other physical quantities are then defined
as derived quantities.
A unit is a defined sample of a quantity.
Dr Alina Mirza, Dept of EE MCS, NUST
In the physical world there are only six fundamental
The branch of physics known as mechanics gives us
the fundamental quantities of length, mass, and
Thermodynamics adds the fundamental quantity of
temperature difference.
Electricity and Magnetism give us the quantity of
electric current.
Optics give us the quantity of light intensity
Chemistry gives us the quantity of amount of
substance .
Dr Alina Mirza, Dept of EE MCS, NUST
SI Units or System International Units – Based
on a defined standard
Dr Alina Mirza, Dept of EE MCS, NUST
Dr Alina Mirza, Dept of EE MCS, NUST
Commonly Encountered Electrical Units
Functional Elements of an Instrument
Instrument Classification
Performance Characteristics
Static Characteristics
Dynamic Characteristics
Methods of Measurement
Types of Errors
Loading Effects
Dr Alina Mirza - Dept of EE MCS, NUST
Dr Alina Mirza - Dept of EE MCS, NUST
• The volt, named for Alessandro Conte Volta, is the SI unit of potential
• Potential Difference is the force that causes charges to move through an
electric circuit.
• On the basis of moving charges, a difference of one volt exists between two
points in a circuit if one joule of energy is required to move a 1-coulomb charge
from the point of lower potential to the point to higher potential
• From this definition, voltage then has the dimensions of joules per coulomb
Dr Alina Mirza - Dept of EE MCS, NUST
• The ampere, named for Andre Marie Ampere,
• Is the SI unit of electric current
• It is a measure of the rate at which electrical charge passes a given point in a
• A current of one ampere will cause a charge of one coulomb to pass a given
point in a circuit in one second
• The quantity symbol for current is represented by the letter I , after the French
word for current,
• we adhere strictly to conventional current flow
Dr Alina Mirza - Dept of EE MCS, NUST
• The ohm, named for George Simon Ohm
• Is the SI unit of electrical resistance
• It is a measure of the opposition to a steady current flow due to the molecular
properties of the conductor
• By definition, the voltage across the element divided by the current
flowing through the element
• Resistance is considered as proportionality constant that linearly relates the
potential difference between two points in a circuit and the current that
results from the potential difference between them (Ohm's law)
• The quantity symbol for resistance is indicated by the letter R
• The unit symbol for ohm
uppercase Greek letter omega (Ω)
Dr Alinais
- Dept of EE
• The farad, named for Michael Faraday
• Is the SI unit of capacitance
• Capacitance is a measure of the charge that is stored on a capacitor as a
function of the applied voltage
• Is equal to the stored charge divided by the voltage across the capacitor
• The quantity symbol for capacitance is indicated by the letter C (and should
not be confused with the unit symbol for coulombs, represented by the letter
• The unit symbol for farads is represented by the letter F
• The farad is an extremely large unit, capacitance units are most commonly
expressed in terms ofDreither
(μF) or picofarads (pF)
Alina Mirza
- Dept of EE MCS, NUST
• The henry, named for Joseph Henry
• Is the SI unit of inductance
• It is a proportionality factor that relates induced voltage in a coil of wire to the
rate of change of current with time
• The quantity symbol for inductance is indicated by the letter L (in italic)
• The unit symbol for henry is represented by the letter H
Dr Alina Mirza - Dept of EE MCS, NUST
• The hertz , named for Heinrich Rudolph Hertz, is the SI unit of frequency
• A frequency of one hertz is defined as one cycle of the waveform per one
• The quantity symbol for frequency is generally indicated by the letter f,
• The unit symbol for hertz is Hz
Dr Alina Mirza - Dept of EE MCS, NUST
Functional Elements of an
Dr Alina Mirza - Dept of EE MCS, NUST
Functional elements of an instruments are divide
into three parts
The physical,
▪ Primary sensing element
▪ Data conditioning element
▪ Data presentation element
Dr Alina Mirza - Dept of EE MCS, NUST
chemical, electrical
quantity, property,
process, variable or
condition to be
measured is referred
to as measurand
An element of an instrument which makes,
first, the contact with quantity to be
measured is called primary sensing element
The first detection of measurand is done by
Generally transducers follows PSE, which
converts measurand into corresponding
electrical signals.
Dr Alina Mirza - Dept of EE MCS, NUST
When output from PSE is not suitable for
actual measurement system, variable
conversion element is required e.g. Analog to
Digital convertors
The original information about measurand
should be retained as it is while performing
Some instruments need variable conversion
element and some do not
Dr Alina Mirza - Dept of EE MCS, NUST
If the output is not enough to drive the next stage,
manipulation is required.
 Manipulation involves change in the numerical
value of the signal.
 Attenuators / Amplifiers.
 Signal conditioning, to obtain signal in pure form
from highly distorted form .eg. Clipping ,clamping,
 Variable conversion + variable manipulation +
signal conditioning = Data Conditioning or Signal
Conditioning element
Dr Alina Mirza - Dept of EE MCS, NUST
When elements of system are physically
separated, it is necessary to transmit the data
from one stage to other. This is done through
data transmission element
Signal conditioning + Data transmission =
Intermediate stage of an instrument
Dr Alina Mirza - Dept of EE MCS, NUST
Transmitted data may be used by the system for
monitoring, controlling or analysis purpose
 The observer should get to data in proper form.
This is done by data presentation element
▪ Monitoring: visual display devices
▪ Record & Analysis: magnetic tapes, recorders, high speed
▪ Control & Analysis: microprocessors, computers,
This stage is known as terminating stage
Dr Alina Mirza - Dept of EE MCS, NUST
How many kilo meters are there in 2.5 miles? If
1 mile = 5280 ft and 1 ft =0.305 m.
How many centi meters are there 56.43 ft? if 1
ft = 0.305 m
What is the weight of 3.7 𝑙𝑏 mass in Newton? if
1 lb-weight = 4.448N
A 110 V electric motor uses 5.8 A. If the motor is
87% efficient, then how many horsepower the
motor will generate? If 1 hp = 746Watt
Dr Alina Mirza, Dept of EE MCS, NUST