Automation Module
Engineering Foundation Course
2011
Contributors to the Course
Steven Laycock: Technology Leader for Process Control and Automation in Unilever Europe
since 2003 and the Global Engineering Excellence Team. Joined Unilever (Leeds) in 1996, after
working for an independent systems integrator.
Stuart Dow: Systems Development Manager with Haden Freeman Ltd. (engineering
design and consultancy company). 13 years as engineer & manager working on projects in
a variety of industry sectors.
Karam Rehani: Head of Instrumentation & Controls in Unilever India & AAMET since 1994.
Joined Unilever (HLL) in 1981 & has worked at various locations manufacturing soaps,
detergents, personal products & chemicals. Before joining Unilever, worked for 9 Yrs with
Leading fertiliser co’s in India.
Adhi Winata K : Instrumentation, Control, Automation & Electrical Manager in Unilever
Indonesia. Joined Unilever in 2006. Before joining Unilever, worked with
telecommunication company.
Endress + Hauser : Live Product Demo
Rockwell Automation : Live Product Demo
Siemens : Totally Integrated Automation Concept (Presentation Content)
Objective
What are we going to cover today
3 key areas
- Understanding of the use of control systems
- Key knowledge necessary to manage an automation project
- Reasons to choose from the control options available
Agenda
Section 1:
Introduction to Control
Building blocks – Measurement & Action
Example Equipment (Endress & Hauser)
Section 2:
Building Blocks – Evaluation & Logic
Pack Line Case Study : OMAC (Rockwell)
Section 3:
Automation Projects & Industry Standards
Process Plant Case Study : Implementation of ISA S88 & ISA S95 (Rockwell)
Section 4:
Multiple Choice Questionnaire
Agenda
Section 1:
Introduction to Control
Building blocks – Measurement & Action
Example Equipment (Endress & Hauser)
Section 2:
Building Blocks – Evaluation & Logic
Pack Line Case Study : OMAC (Rockwell)
Section 3:
Automation Projects & Industry Standards
Process Plant Case Study : Implementation of ISA S88 & ISA S95 (Rockwell)
Section 4:
Multiple Choice Questionnaire
Reasons for Automation
Quality :
Better quality, fewer rejects
Marketing:
A marketing push may
require increased
production, re-branding,
re-packaging or new
formulations for example,
or a requirement to search
for new growth or markets
Commercial:
Higher output, lower
utility costs, better
yield, less labour
It is to realize highest productivity enhancements by intelligently connecting quality,
speed, and cost and finding the optimal balance between all three
Challenge for Automation
Automation Characteristics
Safety for humans &
machines :
• Safety Interlock
• Alarm Management
• Safety Integrated Solutions
(SIS)
Diagnostic functionalities
that enable fast detection
and correction of errors :
• Maintenance Station
• Engineering Station
Software for Controller and
HMI programming :
• STEP 7 (Siemens)
• RSLogix 5000 (Allen-Bradley)
Standard data transparency
across all automation levels :
• Communication Protocol
• Logger / Historian
• Report
IT Security in the network :
• Restricted Access
• Firewall
• Encoding
• VPN Network
Industrial capability
equipment with highest
robustness :
• Industrial Type Hardware
Automation System Components
The Automation Pyramid
ERP
Enterprise Resource Planning System
Basic functions of the business.
Production Planning, Material Management
MES
Manufacturing Execution System
Measure and control critical production activities.
Equipment tracking, product genealogy, scheduling,
KPI monitoring
SCADA
“Supervisory Control & Data Acquisition” System
Interface to monitor & control the manufacturing plant
HMI, Data Logger / Historian, Batch Management
Control Level
Monitor & control the manufacturing plant
PLC - “Programmable Logic Controller”, PC Based
Controller, Single / Multiple Loop PID (Proportional, Integral, Derivative)
Controller
Field Level
Final executor of the manufacturing plant
Sensors, Actuators, I/O Module, Hardware
Automation System Components
Response time and hierarchical level
ERP
Planning
Level
(Enterprise Resource
Planning)
MES
Execution
Level
(Manufacturing
Execution System)
SCADA
(Supervisory Control
and Data Acquisition)
Supervisory
Level
DCS
(Distributed
Control System)
Control
Level
PLC
(Programmable
Logic Controller)
ms
seconds
hours
days
weeks
month
years
Automation System Components
Layer
ERP
Function
Covers all basic
functions of the
business
Application Example
Product Example
• Production Planning
SAP
• Orders
Oracle
• Finance
• Material Management
MES
Measure and
control critical
production
activities
• Equipment tracking
SIMATIC IT
• Product genealogy
FactoryTalk Integrator
• Scheduling
InSQL
• KPI monitoring
• Workflow
SCADA
Control
Field
Interface to
monitor & control
the manufacturing
plant
Monitor & control
the manufacturing
plant
Final executor of
the manufacturing
plant
• Operator Station
WinCC, FT View, InTouch
• Engineering Station
• Batch Control
SIMATIC Batch, FTBatch, InBatch
• Logger
• PLC
SIMATIC S7-400, ControlLogix
• PID Controller
SIPART, Eurotherm T640
• PC Based Controller
ACCOSS (Invensys Integrator)
• Motion Controller, CNC
SIMOTION, SINUMERIK
• I/O Module
SIMATIC ET200 M, Flex I/O
• Field Instruments
E+H, Emerson, SITRANS
• Actuator
Motor, Valve
Automation System Components
Application Example : Siemens Totally Integrated Automation
Production
Planning
Production
Order
Management
Event Logger
HMI Client
Batch Client
Material
Management
Detailed
Production
Scheduling
Data Logger
Server
Product
Specification
Management
HMI Server
Batch Server
Production
Operations
Recording
Automation System Components
Real Plant Example : Skin Care Processing Plant Cikarang
Basics
How Do We Control?
Information
Monitor
Evaluate
Action
Basics
An Everyday Example
We monitor the temperature.
Is it too cold or too hot?
If so we adjust the tap to correct.
Wait for a bit (system dynamics)
If temperature OK then have shower
Else if temperature not OK adjust again
(but with benefit of knowing impact of last
adjustment)
Go to ‘Wait for a bit’ and repeat.
Basics
Control Loop
Instrumentation
Engineering Foundation Course
2011
Agenda
Section 1:
Introduction to Control
Building blocks – Measurement & Action
Example Equipment (Endress & Hauser)
Section 2:
Building Blocks – Evaluation & Logic (Process & Packing Line)
Pack Line Case Study : OMAC (Rockwell)
Section 3:
Automation Projects & Industry Standards
Process Plant Case Study : Implementation of ISA S88 & ISA S95 (Rockwell)
Section 4:
Multiple Choice Questionnaire
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Flow Measurement
1. Velocity
Measure the velocity flowrate
Example :
Magnetic
Turbine
Ultrasonics
2. Inferential
Determine flow by measuring some other physical property such as differential pressure,
area meter, impact force, etc and then correlate it to flow
Example :
Differential Pressure (DP) : Orifice, Pitot Tube, Venturi
Area Meter
: Rotameter
Impact Force
: Target
3. Mass
Measure the mass flowrate
Example :
Coriolis Mass Flowmeter
Thermal Mass
Flow Measurement
1. Velocity Flow : Magnetic Flowmeter
• A magnetic field at right angles to the flow
stream is generated
• Two opposing electrodes measure the
voltage produced by the fluid moving
Flow Measurement
1. Velocity Flow : Magnetic Flowmeter
Video Time !!!
Flow Measurement
1. Velocity Flow : Magnetic Flowmeter
Advantages :
1.
2.
3.
4.
5.
Capable of handling extremely low flow
Having very low pressure drop (no obstruction), minimize pumping cost
Suitable for most acids, bases, waters, and aquaeous solutions, because
the lining materials are corrosion resistant
Widely used for slurry services
Can be used as bidirectional meters
Limitations :
1.
2.
3.
Work only with conductive fluids (can not measure pure substances,
hydrocarbons, and gases)
Electrical installation care is essential (Proper Grounding)
Flow measurement inaccuracy due to fluids with magnetic properties
(Liquid Sodium and its solutions)
Flow Measurement
1. Velocity Flow : Turbine/Paddlewheel
A rotor (like a propeller) is supported by bearings to allow free
rotation in the fluid flow.
As the blades spin in the moving flow a pickup device counts the
passing rotor blades and generates a frequency.
As this frequency is
proportional to the
rate of flow and we
know how much
quantity each pulse
represents we can
calculate the
volumetric flow.
Flow Measurement
1. Velocity Flow : Turbine/Paddlewheel
Advantages
1.
2.
3.
One of the most accurate flow meter (use for trading)
Having a fast response
Not sensitive to changes in fluid density (though at very low specific
gravities, rangeability may be affected)
Limitations
1.
2.
3.
4.
Not recommended for measuring steam
Sensitive to dirt
Can not be used for highly viscous fluids or for fluids with varying
viscosity
Potential for being damaged by over-speeding (esp. during
commissioning or start up)
Flow Measurement
2. Inferential Flow : dP Orifice Plate
Orifice plate : a flat piece of metal with a hole bored
in it.
p+
p-
A dP (differential pressure) is
created across the plate.
Q
C d  Aorifice
A

1   orifice 
 A

 pipe 
2

2  ( p  p )

D
d
Flow Measurement
2. Inferential Flow : dP Orifice Plate
An instrument that can measure dP is
connected by pipework (called impulse
lines) to a tapping point on either side of
the plate.
The square root of the dP measured is
proportional to the flow. (Normally
accounted for in the electronics of the
measuring instrument)
Flow Measurement
2. Inferential Flow : dP Orifice Plate
Video Time !!!
Flow Measurement
2. Inferential Flow : dP Various
Pitot Tube
Venturi Tube
Flow Nozzle
Elbow Taps
Flow Measurement
2. Inferential Flow – dP Various
Type
Orifice
Advantages
Limitation
Wide range of applications
Low accuracy
Simplest & cheapest among dp types (except big size)
High irrecoverable pressure loss
Sturdy
Pitot Tube
Applicable for measurement of large flows
Low accuracy
Can be used to obtain the velocity profiles
Depend much on velocity profiles in one point
Very Low pressure loss
Venturi Tube
Low Pressure Loss
More expensive than orifice
Resistant to abrasion
Installation is more difficult
Can be used to measure dirty fluids & slurry
Elbow Taps
Venturi Nozzle
Low cost solution for large pipe
Inaccurate measurement
Very Low Pressure Loss
Requiring high flow velocities & short radius elbow
Less expensive than venturi tube
Higher Pressure Loss than venturi tube
Resistant to abrasion
Installation is more difficult
Flow Measurement
3. Mass Flow : Coriolis Effect
Tube(s) are forced to oscillate at their natural
frequencies perpendicular to the flow direction.
The resulting Coriolis forces induce a twist movement in
the tubes which is measured and is related to the mass
flow.
Flow Measurement
3. Mass Flow : Coriolis Effect
Video Time !!!
Flow Measurement
3. Mass Flow : Coriolis Effect
Two most common types are the
Straight Tube
1.
2.
3.
4.
Used mainly for multiphase fluids
and for fluids that can coat or clog
since the straight type can be easily
cleaned
Having a low pressure loss
Reduces the probability of air and
gas entrapment
Must be perfectly aligned with the
pipe
Curved Tube
1.
2.
3.
4.
5.
Having a wider operating range,
measures low flow more accurately
Available in larger sizes
Tends to be lower in cost
Having a higher operating
temperature range
More sensitive to plant vibrations
Flow Measurement
3. Mass Flow : Coriolis Effect
Advantages :
•
Directly measures mass flow with high accuracy
•
High rangeability
•
Directly measure density
•
Highly independent of the flow profile and fluid properties (specific gravity
and viscosity)
•
Can be used for many different applications, including corrosive fluids
Limitations :
•
High Price
•
Can not be used for liquids with any significant gas content
•
Not available for large pipelines
•
Not suitable for low pressure gases
Flow Measurement
Other Methods
Vortex Shedding
Ultrasonic
Thermal Mass Flowmeter
Variable Area / Rotameter
Weir & Flume
Target
Flow Measurement
Flowmeter Comparison Table
Flow Measurement
Flowmeter Comparison Table (cont’d)
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Level Measurement
1. Pressure / Force
Pressure
Buoyancy Force
: Differential pressure, Diaphragm, Air bubblers
: Displacer
2. Position (height) of the surface
Wave
Nuclear radiation
Electrical Properties
Mechanical Contact
3. Weight
Load Cells
: Radar, ultrasonic, Guided Radar (TDR)
: Capacitance, Conductance
: Floats, Tuning fork, Paddle wheel
Level Measurement
Pulse 6 GHz
Radar
Pressure
Guided Wave
Radar TDR
FMCWPulse Capacitance
24 GHz Radar
Ultrasonic
Level Measurement
1. Pressure Static Head
Pressure/Static Head: (also known as hydrostatic)
- Based on the height of the liquid head
& the density of the liquid
- Accurate level calculation requires known
& constant density
Atmospheric
Vessel
Pressurized
Vessel
Advantages :
1. Have a wide range of measurement
2. Straightforward calibration
Limitations :
1. Affected by changes in liquid density (only
for liquids with fixed SG)
2. Susceptible to dirt or scale entering the
tubing
Level Measurement
2. Position of Surface : Wave
Wave is transmitted to target, reflected, and total transit time is determined
Type
Wave Source
Carrier Medium
Wave Speed
Radar
Electromagnetic
Wave (4-30 GHz)
Not needed (able to
propagate in empty /
vacuum space)
Speed of Light
(300,000 km/s)
Ultrasonic
Mechanical Wave
(> 20 kHz)
Needed (air, liquid, solid)
Speed of sound
(344 m/s)
Free WaveFree Wave
Ultrasonic
Radar
Guided Wave
Guided Radar
Level Measurement
2. Position of Surface : Wave
Type
Advantages
1.
Able to measure the level without making
physical contact with process material
2.
Unaffected by changes in the composition,
density, moisture content, electrical
conductivity, and dielectric constant of the
process fluid
Ultrasonic
Radar
Guided
Radar
Limitation
1.
May not be used if vapour space of the
material is dusty, or it contains foam, water
vapour, or mists
2.
Not applicable should the material has
sound-absorbing surface (fluffy solids)
3.
Reliable performance for difficult slurry or
sludge-type services
3.
Require a consistent temperature, since it is
affected the speed of sound
1.
Able to measure the level without making
physical contact with process material
1.
Not applicable for low-dielectric material
that absorb the microwave
2.
Unaffected by changes in the composition,
density, moisture content of the process fluid
3.
Changing vapour and foam has less effect
than on ultrasonic type
4.
Reliable performance for applications of
medium difficulty, such as fuming acids,
asphalt, LNG, tars, and other heavy
hydrocarbons
1.
Able to measure liquid interface level (with
some conditions related with dielectric constant
of the material & no emulsion layer)
1.
Not applicable for low-dielectric material
that absorb the microwave
Level Measurement
2. Position of Surface : Electrical Properties
Capacitive
•
•
•
•
•
Measures the changing electrical capacitance
Applicable for both conductive and nonconductive fluids
Provide both continuous and point measurement
The dielectric constant of the fluid must remain constant
Can not measure liquid interface
Conductive
•
•
•
•
Electric current flows through the fluid, container wall
and the probe which actuates a relay
Applicable for conductive fluids only
Provide only point measurement
Can provide differential level control (three-probetype)
Level Measurement
2. Position of Surface : Nuclear Radiation
•
A radioactive source radiates through the vessel. The gamma
quantum is seen by the radiation detector (such as a Geiger counter)
and is transformed into a signal
•
Unaffected by temperature, pressure, and corrosion
•
Applied where other types of measurement cannot be used
Level Measurement
2. Position of Surface : Mechanical Contact
Tuning Fork (Vibration)
•
•
•
Keeping the probe vibrate in its natural frequency
Relay triggered when process material in the tank reaches
the vibrating elements and damps out the vibration
Applicable for both liquid and solid material
Rotating Paddle Switch
•
•
•
Small synchronized
motor keeps the paddle
in motion at very low
speed
When level raised to the
paddle, it is stopped
Applicable for solid
material
Float
•
•
Applicable for
liquid material
Applicable for both
point and
continuous
measurement
Level Measurement
3. Load Cells
The strain gauge (either foil or
semiconductor) measures the stress
which is introduced into a metal
element, both compression & tension
A bending beam type design
uses strain gauges to monitor the
stress in the sensing element
when subjected to a bending force.
Level Measurement
3. Load Cells Type
Type
Explanation
Designed to operate in compression only
Compression
(Canister)
Load can be applied at one end only, for some
types it can be compressed by force at both
ends
Shear Beam
Fixed rigidly at one end with the force being
applied to the other end
Bending
Beam
It consists of a straight beam attached to a base
at one end and loaded at the other. Its shape can
be that of a cantilever beam, a binocular
design, an S-shaped or a ring design .
Ring Torsion
Round and flat bending beam sensors
consisting of bonded foil strain gages
encapsulated in a housing
Helical
The operation of a helical load cell is based on
that of a spring. A spring balances a load force
by its own torsion moment
Picture
Level Measurement
3. Load Cells Comparison Table
Level Measurement
Level Sensor Comparison Table
Level Measurement
Level Sensor Comparison Table (cont’d)
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Temperature Measurement
1. Voltage
 Thermocouples
2. Resistance
 RTD
 Thermistor
3. Radiation Pyrometer (Infra Red)
 Optical
 Ratio / Two-Color
 Broadband (Total) Radiation
4. Material Expansion
 Liquid-in-glass
 Bimetallic
 Filled system
Temperature Measurement
1. Thermocouples
A thermocouple consists of two dissimilar metals,
joined together at one end. When the junction of the
two metals is heated or cooled a voltage is produced
that can be correlated back to the temperature.
Temperature Measurement
Thermocouples Type
Wire Material
Range (in °C)
Type
Scale Linearity
Positive
Negative
B
Pt 70% Rh 30%
Pt 94% Rh 6%
E
Chromel
J
Min
Max
Atmosphere
Environment
Recommended
Favorable Points
Less Favorable Points
Good at high temps. Poor
below 535 °C
Inert or Slow
Oxidizing
982
Good
Oxidizing
Highest mV/°C
Larger drift than other
base metal couples
0
816
Good; nearly linear from
150°C to 425°C
Reducing
Most economical
Becomes brittle below
0°C
-184
1260
Good; most linear of all
TCs
Oxidizing
Most Linear
More expensive than T
or J
Platinum
0
1649
Good at high temps. Poor
below 535 °C
Oxidizing
Small size, fast
response
More expensive than K
Pt 90% Rh 10%
Platinum
0
1760
Good at high temps. Poor
below 535 °C
Oxidizing
Small size, fast
response
More expensive than K
T
Copper
Constantan
-184
399
Good but crowded at low
end
Oxidizing or
reducing
Good reststance to
corrosion from
moisture
Limited temperature
Y
Iron
Constantan
-129
982
Good; nearly linear from
150°C to 425°C
Reducing
0
1860
Constantan
-184
Iron
Constantan
K
Chromel
Alumel
R
Pt 87% Rh 13%
S
Not Industrial Standard
Temperature Measurement
2. RTD (Resistance Temperature Detector)
Measure temperature by correlating the resistance of the RTD
element with temperature.
The RTD element is made from a pure material whose resistance at
various temperatures has been documented. It has a predictable
change in resistance as the temperature changes
RTD element construction type
Wire-Wound
•
•
Winding the wire on a glass or ceramic bobbin and sealing
with molten glass
Limited by strain induced at higher temperature
Coil Elements
•
•
•
Threading a wire helix through a ceramic cylinder
Allows the wire coil to expand more freely over temperature
Not suited for extreme vibration
Thin Film
•
•
Depositing a thin film on a ceramic substrate
Small, fast, inexpensive, less stable
Temperature Measurement
RTD Detector Type
Metal
Range
(in °C)
Min
Platinum
Nickel
-200
-196
Max
850
Ice Point
Resistance
Characteristic
Thin Film Type :
100, 1000 Ω
Most Linear
Wire-wound Type :
100, 200, 500 Ω
Widely used
120, 500, 1000 Ω
Not linear
316
Strain-sensitive
Highest Temperature coefficient
Copper
-196
120
Used in electrical machinery
due to very low reactance
10, 100 Ω
RTD Wiring configuration
2-wire
•
•
•
Poor Accuracy
No compensation for resistance of
the connecting wires
Transmitter must be placed very
near with the sensor
3-wire
•
•
Better accuracy than 2-wire
Two leads to the sensor are
on adjoining arms, therefore
the lead resistance is
cancelled out
4-wire
•
•
Best accuracy
Another pair of wires to form an
additional loop that cancels out
the lead resistance
Temperature Measurement
Thermocouples Vs RTD
Characteristic
Thermocouple
RTD
Measurement Range
Wide
Narrow
Response Time
Fast
Slow
Less Linear
More Linear
Cheap
Expensive
Accuracy
Less Accurate
More Accurate
Sensitivity
Less sensitive
More Sensitive
Repeatability
Fair
Excellence
Long-Term Stability
Fair
Good
Self Heating Effect
Medium
N/A
Fair
Excellent
Medium
High
Linearity
Price
Point (end) sensitive
Lead Effect
Temperature Measurement
3. Optical
The most basic design consists of a lens to focus the infrared (IR) energy
on to a detector, which converts the energy to an electrical signal that can
be displayed in units of temperature after being compensated for ambient
temperature variation.
Infrared pyrometers allow users to measure temperature in applications
where conventional sensors cannot be employed. Specifically, in cases
dealing with moving objects ( i.e., rollers, moving machinery, or a
conveyor belt),
Temperature Measurement
Temperature Sensor Comparison Table
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Pressure Measurement
1. Elastic Pressure Chamber (Mechanical)
Bourdon Tubes
Diaphragm
Bellows
2. Electronics
Capacitive
Strain Gauge (Piezoresistive)
Piezoelectric
Inductive
3. Liquid Level Column
Manometer
Pressure Measurement
1. Mechanical
Bourdon
Bellows
A bent oval tube.
One end of the tube is linked to
the process pressure, and the
other end is sealed and linked
to the mechanism operating
the Pointer
Shapes :
C, Spiral, Helical
One-piece axially
expandable and
collapsible element.
Consists of many folds
Diaphragm
Converts the increasing
process pressure on one side
of the disk into a mechanical
movement by monitoring the
bulging of the disk
Pressure Measurement
2. Electronics
A typical electronics pressure transmitter consists of two parts:
1. Primary element
Converts the pressure into an displacement / torque / mechanical value to be read by
the secondary value. It may be diaphragm, bellows, etc
2. Secondary element
The electronics that output from the primary element to a readable signal. It may be strain
gauges, capacitive, piezoelectric, etc
Pressure
Primary Mechanical
Element
- Displacement
- Torque
Secondary
Element
Electric
- Resistance
- Capacitance
- Voltage
- Current
Pressure Measurement
2. Electronics
Strain Gauges / Piezoresistive
Piezoresistive material
changes its resistance
when strain is applied
Capacitive
dP ceramic cell
ceramic
membrane
ceramic
body
process
pressure
capacitor
plates
C1
C2
fill fluid
The inlet pressure activates a diaphragm that is
mounted between two fixed plates. This causes a capacitance change
additional temperature
sensor for permanent
self monitoring
Pressure Measurement
2. Electronics
Inductive
The inlet pressure activates a
diaphragm / bellows moves a
magnetic core inside the transformer.
It creates an imbalance that is
measured in the electronics
Piezoelectric
The inlet pressure activates a diaphragm / bellows that
applies strain on a crystal (e.g., quartz). The strained
quartz produces an electrical charge that is measured by
the electronics
Pressure Measurement
Pressure Measurement Reference
Absolute
1. Gage pressure
Reference : Atmospheric pressure
2. Absolute pressure
Reference : Complete vacuum
Level
3. Differential pressure
Difference between two pressure levels
Gauge Pressure
(psig, bar)
DP
Atmospheric Pressure
Vacuum Pressure
(-psig, -bar)
Absolute Pressure
(psia, bara)
Absolute Zero Pressure
Gauge
Pressure Measurement
Pressure Sensor Comparison Table
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Analytical Measurement
pH
Conductivity
Gas Detector
MC Meter
Chlorine Meter
Turbidity
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Measurement
Position
Position and distance sensors detect the
presence or not of items on the move. This can
be used to identify when an item arrives, count
how many items have passed or when an item
has left.
Position technologies include photoelectric,
laser, mechanical switches, proximity switches
and pressure sensors.
Measurement
Colour
Colour sensors can detect the presence or not
of a successful operation. Has the label been
printed, has the bottle got the right fluid in it, did
the shrink wrap go on successfully
Measurement
Machine Vision
Machine vision is successfully applied to many industrial inspection problems,
leading to faster and more accurate quality control. Machine Vision allows the
manufacturing industry to
Detect Defects
Calibrate and control the manufacturing process
Optimise the use of resources
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Action
Valves
Solenoid Valves
Switching a pneumatic air supply to a
valve or piston cylinder
Modulating / Control Valves
• Achieving precise control of a process fluid
• Usually connected to I/P transducer that
convert electrical signal into pressure
signal
Discrete Valves
• Switching feeds on and off or, when used in conjunction
with other valves, to select routes through pipework
systems
• It is usually connected to solenoid valve that switch on/off
the air supply
Action
Motors
Motors allow us to move things around whether it’s
a pump moving liquids or a conveyor line moving
boxes.
Motor operation (start/stop) is usually controlled in
the MCC (Motor Control Center).
The control circuit in MCC usually consists of
contactors & relays.
Variable Speed Drives (VSD / Inverter) connected
to the motor allows the motor speed to be
controlled.
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Action
Solenoid Valves
Switching a pneumatic air supply to a
valve or piston cylinder
Motors
Stepper motors give precise control of
movement.
Servo drive motors allow added control
functionality (ramp up, ramp down, torque)
and faster positioning.
Action
Equipment
Remote device interfaces allow us to
control and “talk” with an enormous range
of equipment and devices. This can take
the form of a simple on/off control or a
complex data/control interface.
Action
Mechatronics
Building Blocks:
Measurement & Action
I. Monitoring & measurement
1. Process Instrumentation
•
•
•
•
•
Flow Measurement
Level Measurement
Temperature Measurement
Pressure Measurement
Analytical Measurement
2. Packing Line Sensors
II. Action
1. Process Instrumentation
2. Packing Line Actuators
III. Hardware Selection : Which to Pick
Which to Pick
Environment & System
What are the the parameters the device will be exposed to and expected
to perform in during both routine and exceptional circumstances?
What are the performance criteria: speed, size, pass/fail criteria for the
line?
With which chemicals and under what conditions will the device be
expected to operate?
What hazards will be present and does this impact on the choice of
device?
What’s the commercial impact? Cost v benefit.
Which to Pick
ANSI/ISA 60529
Degrees of Protection
Provided By Enclosures
IP XX
Protection
against solid
objects
Protection
against water
Which to Pick
ATEX DIRECTIVES
Minimise, or completely eliminate, the risk of ignition in explosive areas
and to limit the harmful effects in case of an explosion.
Which to Pick
ATEX DIRECTIVES