The document describes upgrading the control system of flow calibration rigs from obsolete to PLC-based control. It provides details on the components, working, and I/O requirements of three electromagnetic flow meter calibration rigs of different pipe sizes. The upgrade aims to increase accuracy and reduce labor by automating calibration using a PLC controller that receives inputs from sensors and actuators and provides outputs to control actuators and record measurements.

1. UPGRADATION OF PLC-BASED CONTROL
OF FLOW CALIBRATI
By: ANKITA KALRA

2. FLOWMETERS
A flow meter is a device used to measure the flow rate or quantity of a gas or liquid moving through
a pipe.
Following are the types of flowmeters:
• Oval Gear meters
• Lobed Impeller meters
• Vortex flow meters
• Swirl flow meters
• Differential pressure flow meters
• Electromagnetic flow meters
• Ultrasonic flow meters
• Coriolis mass flow meters
• Thermal Mass flow meters

3. Electromagnetic Flow meter
Measurment Principle:
The potential difference is sensed by
electrodes aligned perpendicular to the
flow and the applied magnetic field.
The physical principle at work is
Faraday's law of electromagnetic
induction.
The magnetic flow meter requires a
conducting fluid and a nonconducting
pipe liner.

4. Electromagnetic flow meter (Principle)

5. Electromagnetic flow meter
(Advantages and Limitations)
ADVANTAGES:
• Unobstructed flow passage without projecting
parts.
• No moving parts
• No additional pressure drops.
• Unaffected by changes of density, temperature,
pressure, viscosity.
• Unaffected by contaminations and deposits.
• Can be sterlized.
• Linear relation between flow rate and measured
variable.
• Measuring range can be optimzed.
• Operates in both directions (forward & backward)
• Low maintainance.
LIMITATIONS
Gas inclusions cause error.
For liquids only
Lower conductivity limit 0.05microS/cm

6. Electromagnetic flow meter
(Electrical Connections)
• A magnet coil cable is run parallel to the signal lines. As a result, only one
cable is required between the flowmeter sensor and the transmitter.
• The signal cable carries a voltage signal of only a few millivolts and must,
therefore, be routed over the shortest possible distance. The max. allowable
signal cable length is 50 m (164 ft) without pre-amplifier and 200m (656 ft)
with pre-amplifier.
• Avoid routing the cable in the vicinity of electrical equipment or switching
elements that can create stray fields, switching pulses, and induction. If this is
not possible, run the signal / magnet coil cable through a metal pipe and
connect this to the station ground.
• All leads must be shielded and connected to the station ground potential.

7. Flow meter Calibration Area (RIGs) - Principle

8. Flow meter Calibration Area (RIGs)
• With the help of a pressure and temperature transmitter, the
temperature and pressure of the medium is controlled and working
conditions of the RIG are maintained.
• Pump is used to regulate the flow-rate of the medium inside the
pipes of the RIGs. The flow thus generated is measured by the
reference flow meter and the flow meter being calibrated or
verified.
• The accumulated pulse quantity over a number of cycles is recorded
and the total measured volume at standard temperature and
pressure is calculated for both (Master and Process masters) the
flow meters.

9. Flow meter Calibration Area (RIGs)
• The comparison of the results gives a reliable result of the flow-rate
at a standard temperature and pressure. The difference between the
readings of the reference flow meter and meter under test (MUT) for
different ranges of measurement gives the percentage error, accuracy
and other reliable results.

10. Flow meter Calibration Area (RIGs)
Method of Callibration
• Volumetric Method:
Procedure to measure the volume flow rate of a liquid using a
callibrated volume meaurment tank and measuring the fill time.
• Gravimetric Method:
The volume of the liquid is measured by weighing, taking into account
the density and the amount of air displaced.

11. Description of RIGs
• There are 3 RIGs for its calibration of Electromagnetic flow-meters
(ProcessMaster FEP300) depending on the bore size of flow meters
which are as follows:
RIG -1 : 15-150mm
RIG -2 : 150-200mm
RIG -3 : 200-400mm

12. Description of RIG-1
• Water from the water pool (capacity : 740Ltrs) is pulled with help of a
motor controlled by a variable frequency drive (VFD) and is pumped
into the pipe with help of a pump which then reaches the inlet
actuator VA-7 (butterfly valve with manual over ride) on the RIG.
• The function of the inlet actuator is to move the incoming water into
the pipe. Water from the inlet actuator is loaded to the flow-meters
under test with help of hydraulic slider, in series with the MUT 1.1,
MUT 1.2 & MUT 1.3.
• Pressure and temperature transmitters are used to indicate the
standard conditions of pressure (10 bar) and temperature (20 - 50
degrees) respectively for the fluid inside pipes for further regulations
if required.

13. Description of RIG-1
• Thereafter, the fluid from the MUT reaches the span or zero span line
as directed by the controller. On entering the zero span line, the fluid
movement is controlled by VA-1 before it reaches MM1-1 (calibrated
at three times greater accuracy than that of MUTs) which provides
the reference flow-rate of fluid. The span and zero-span calibrations
are performed so as to provide a multiplying factor to the losses
through the RIG.
• The fluid then moves to the VA High and Low flow area where the
single acting positioner (AV2) controls the percentage flow of the fluid
through the pipe as per the controller’s command. The positioner
receives an external 4-20mA signal and converts it into a pneumatic
output (4mA - 10% flow-rate, 20mA- 90% flow-rate), which produces
motive force that positions the power actuator, connected electrically
to it.

14. Description of RIG-1
• Thereafter, diverter and the solenoid valve are used to direct the flow
of fluid into the water pool or water tank, the fluid from the water
pool is pumped back into the pipe to continue the cycle.

15. Description of RIG-2
• Thereafter, the fluid from the MUT reaches the span or zero span line as
directed by the controller. On entering the zero span line, the fluid movement
is controlled by VA-1 before it reaches MM2-1 (calibrated at three times
greater accuracy than that of MUTs) which provides the reference flow-rate of
fluid. The span and zero-span calibrations are performed so as to provide a
multiplying factor to the losses through the RIG.
• The fluid then moves to the VA High and Low flow area where the single
acting positioner (AV2) controls the percentage flow of the fluid through the
pipe as per the controller’s command. The positioner receives an external 4-
20mA signal and converts it into a pneumatic output (4mA - 10% flow-rate,
20mA- 90% flow-rate), which produces motive force that positions the power
actuator, connected electrically to it.
• Thereafter, diverter and the solenoid valve are used to direct the flow of fluid
into the water pool or water tank, the fluid from the water pool is pumped
back into the pipe to continue the cycle.

16. Description of RIG-3
• The fluid then moves to the VA High and Low flow area where the
single acting positioner (AV2) controls the percentage flow of the fluid
through the pipe as per the controller’s command. The positioner
receives an external 4-20mA signal and converts it into a pneumatic
output (4mA - 10% flow-rate, 20mA- 90% flow-rate), which produces
motive force that positions the power actuator, connected electrically
to it.
• Thereafter, diverter and the solenoid valve are used to direct the flow
of fluid into the water pool or water tank, the fluid from the water
pool is pumped back into the pipe to continue the cycle.

17. Load Calculation
SN
o.
Item VA Unit Qty. Total VA Unit
1 Actuators 12.24 26 318.24
2 VA High Flow Positioner 9.7 3 29.1
3 VA Low Flow Positioner 9.7 3 29.1
4 PT 0 3 0
5 RTD 0.288 3 0.864
6 Solenoid Valve 8 12 96
7 Master Meters 20 12 240
8 Motor (Rig -1 & 2) 11000 2 22000
9 Motor (Rig 3) 160000 1 160000
10 Universal Counter 60 3 180
11 CPU 480 3 1440
12 VFD 210 3 630
Sub Total 184963.304
Starting Current 1.2
Total POwer 221955.9648

18. UPGRADATION TO PLC CONTROL OF FLOW CALIBRATI
• Increase accuracy of the flow calibrati.
• The existing system was obsolete.
• Labor reduction.

19. INPUT OUTPUT COUNTS
• The Input Output system provides the physical connection between
the field devices and the controller. The I/O card reveals a terminal
strip where the devices connect.
• There are different kinds of I/O cards which serve to condition the
type of input or output so that the CPU can use it for its logic. Its
simply a matter of determining whatinputs and outputs are needed,
filling the rack with appropriate cards and then addressing them
correctly in the CPU's program.
• The input devices can consist of digital or analog devices, the digital
cards handle the dicrete devices which give a signal that is either on
or off such as a pushbutton, limit switches or selector switches. The
analog cards handles voltage to current conversion (eg. 0 to 20mA)
into diigital equivalents which can be understood by the CPU. For
example Pressure transducers and flow meters.

20. INPUT OUTPUT COUNTS
• Output devices too can be analog or digital type, the digital cards are
either used to turn on or off such as lights, LEDs. The analog card
converts the digital value sent by the CPU to its real world voltage or
current. Typical values range from 0-10V and 0-20mA.
• The following are the I/O counts given to the controller :
Instrument Signal To From
Drive DI Drive Mains PLC
Drive DI Mains On PLC
Drive DI Mains Off PLC
Drive DI Emergency Switch PLC
Drive DI Drive Start PLC
Drive DI Drive Stop PLC

21. INPUT OUTPUT COUNTS
Instrument Signal To From
Drive DI Drive Fault PLC
Drive AI C100 PLC
Drive DO PLC Drive Start
Drive DO PLC Drive Stop
Drive AO PLC Reference to Drive (Speed Reference +)
Drive AO PLC Reference to Drive (Speed Reference -)
RIG-1
VA-3 DI HIGH FLOW ( Actuator) PLC
VA-4 DI HIGH FLOW (Actuator) PLC
VA-6 DI DRAIN (Actuator) PLC
VA-1 DI LOW FLOW ( Actuator) PLC
VA-2 DI LOW FLOW (Actuator) PLC
VA-7 DI INLET (Actuator) PLC
PT AI PT PLC

22. INPUT OUTPUT COUNTS
Instrument Signal To From
RTD AI RTD PLC
MM-1-1 AI MM-1-1 PLC
MM-1-2 AI MM-1-2 PLC
HIGH FLOW ( Actuator) DO PLC HIGH FLOW ( Actuator)
HIGH FLOW (Actuator) DO PLC HIGH FLOW (Actuator)
DISCHARGE (Actuator) DO PLC DISCHARGE (Actuator)
LOW FLOW ( Actuator) DO PLC LOW FLOW ( Actuator)
LOW FLOW (Actuator) DO PLC LOW FLOW (Actuator)
INLET (Actuator) DO PLC INLET (Actuator)
Solenoid Valve (for air vent) DO PLC Solenoid Valve (for air vent)
Solenoid Valve ( for air vent ) DO PLC Solenoid Valve ( for air vent )
HIGH FLOW (Positioner ) AO PLC HIGH FLOW (Positioner )
LOW FLOW (Positioner ) AO PLC LOW FLOW (Positioner )
SOLENOID VALVE1 (FOR DIVERTER) DO PLC SOLENOID VALVE1 (FOR DIVERTER)

23. INPUT OUTPUT COUNTS
Instrument Signal To From
Alarm (RED) DO PLC Alarm (RED)
Alarm (YELLOW) DO PLC Alarm (YELLOW)
Alarm (GREEN) DO PLC Alarm (GREEN)
Alarm (BLUE) DO PLC Alarm (BLUE)
Emergency Switch DO PLC Emergency Switch
Optical Switch DO PLC Optical Switch
RIG -2
VA-3 DI HIGH FLOW ( Actuator) PLC
VA-4 DI HIGH FLOW (Actuator) PLC
VA-6 DI DRAIN (Actuator) PLC
VA-1 DI LOW FLOW ( Actuator) PLC
VA-2 DI LOW FLOW (Actuator) PLC
VA-7 DI INLET (Actuator) PLC
PT AI PT PLC

24. INPUT OUTPUT COUNTS
Instrument Signal To From
RTD AI RTD PLC
AI MM-2-1 PLC
AI MM-2-2 PLC
VA-4 DO PLC HIGH FLOW ( Actuator)
VA-5 DO PLC HIGH FLOW (Actuator)
VA-6 DO PLC DISCHARGE (Actuator)
VA-1 DO PLC LOW FLOW ( Actuator)
VA-3 DO PLC LOW FLOW (Actuator)
VA-7 Inlet DO PLC INLET (Actuator)
SOLENOID VALVE1 DO PLC SOLENOID VALVE1 (FOR DIVERTER)
Emergency Switch DO PLC Emergency Switch
Alarm (RED) DO PLC Alarm (RED)
Alarm (YELLOW) DO PLC Alarm (YELLOW)
Alarm (GREEN) DO PLC Alarm (GREEN)

25. INPUT OUTPUT COUNTS
Instrument Signal To From
HIGH FLOW (Positioner + Actuator) AO PLC HIGH FLOW (Positioner + Actuator)
LOW FLOW (Positioner + Actuator) AO PLC LOW FLOW (Positioner + Actuator)
RIG -3
VA-7 Inlet DI Actuator PLC
VA-5.1 DI Actuator PLC
VA-8.1 DI Actuator PLC
VA-8.2 DI Actuator PLC
VA-7 Inlet DI Actuator PLC
VA-5.1 DI Actuator PLC
VA-8.1 DI Actuator PLC
VA-8.2 DI Actuator PLC
VA-7 Inlet DI Actuator PLC
VA -6 Drain DI Actuator PLC
AI PT PLC AI

26. INPUT OUTPUT COUNTS
Instrument Signal To From
RTD AI RTD PLC
AI MM-3-1 PLC
AI MM-3-2 PLC
VA-7 Inlet DO PLC Actuator
VA-5.1 DO PLC Actuator
VA-8.1 DO PLC Actuator
VA-8.2 DO PLC Actuator
VA-1 DO PLC Actuator
VA-3 DO PLC Actuator
VA-2 DO PLC Actuator
VA-5.2 DO PLC Actuator
VA-5.1 DO PLC Actuator
Emergency Switch DO PLC Emergency Switch
Alarm (RED) DO PLC Alarm (RED)

27. INPUT OUTPUT COUNTS
Instrument Signal To From
Alarm (YELLOW) DO PLC Alarm (YELLOW)
Alarm (GREEN) DO PLC Alarm (GREEN)
Alarm (BLUE) DO PLC Alarm (BLUE)
Optical Switch DO PLC Optical Switch
VA High Flow AO PLC HIGH FLOW (Positioner + Actuator)
VA Low Flow AO PLC LOW FLOW (Positioner + Actuator)
Alarm (YELLOW) DO PLC Alarm (YELLOW)
Alarm (GREEN) DO PLC Alarm (GREEN)
Alarm (BLUE) DO PLC Alarm (BLUE)
Optical Switch DO PLC Optical Switch
VA High Flow AO PLC HIGH FLOW (Positioner + Actuator)
VA Low Flow AO PLC LOW FLOW (Positioner + Actuator)

28. INPUT OUTPUT COUNTS
C1N3DO810 - 16 Ch. - 4cards
C1N3DI810 - 16 Ch. - 4cards
AO815X- 8 Ch.- 2 cards
AI815X - 8Ch. -3cards
AI AO DI DO
21 9 54 54

29. PANEL DESCRIPTION :
• The profibus master controller is connected to two profibus slave
controllers through ethernet (8 port) switch, which further connects
to the software on the computer. This entire setup controls the input
output cards which are powered by the power supply units (PSU) at
10amps. The profibus master controller works with AC800F
(Freelance) software, RS 485 cable on a profimaster card (standard).
• The ethernet switch (100m) boosts the speed of communication and
uses TCP/IP protocol at 10/100Mbps. (The controller requires a
1000Mbps and the console requires 100Mbps).
• Backup power supply provided for power redundancy connected to
MCB and diode-O-rings for switching power between PSU-1 & PSU-2,
PSU-3 & PSU-4 and PSU-5 & PSU-6.

30. PANEL DESCRIPTION :
• The MCB connections for the panel are made as follows:
MCB-1 (40Amps): Main switch (UPS incomer)
MCB-2 (6Amps): PSU-1
MCB-3 (6Amps): PSU-2
MCB-4 (4Amps): PSU-3
MCB-5 (4Amps): PSU-4
MCB-6 (4Amps): PSU-5
MCB-7 (10Amps): PSU-6
MCB-8 (16Amps): Transmitter
MCB-9 (6Amps): Fan & LED
MCB-10 (4Amps): Spare

31. PANEL DESCRIPTION :
• The PSU connections for the panel are made as follows:
PSU-1 & PSU-2 (10Amps): For master and slave controller connected
through ethernet switch
PSU-3 & PSU-4 (5Amps): For Input and output cards
PSU-5 & PSU-6 (20Amps): Field instruments (Transmitters).
• Diode-O-Ring is used for switching power supply between PSU
within milliseconds before power output goes low.
• The I/O cards are looped, i.e. the cards are connected to the
transmitter or the computer which are further connected to feild
devices. Power consumption for 1 channel in I/O card is 8mA.
• The bottom line of connects to the input from the system or field
instruments and top line connects to the output sent to the system
or the field instruments.

32. PANEL DESCRIPTION :
• The channels 1 & 2 of the PTB (power terminal block) of MCB connect
to the power supply, channels 11 & 12 to the neutral terminal and
finally channels 21 & 22 to the ground. Also each channel requires 2
terminal blocks (fused and unfused).
NOTE: ELCB (Leakage current check) must be used with the MCB on the
drive for better safety precaution methods.

33. FUNCTIONAL CHECK of PANEL (Force check)
• IP address for PC set to 172.16.1.1, since ethernet switch used is
unmanaged type (Incase the password is disabled for the system, and
IP address has been changed, no communication would take place in
the system ).
• I/O channel testing:
Range 0 to 28480
ANALOG OUTPUT (Channel 1)
Software (I/P) Multimeter(O/P)
7120 (25%) 8mA
14300(60%) 12.014mA
21400(73.7%) 15.94mA
21400(75%) 16.002mA

34. FUNCTIONAL CHECK of PANEL (Force check)
ANALOG OUTPUT (Channel 8)
DCS doesn’t require a direct percentage scaling. Values can be fed
accordingly for 0 = 0Kg and 28480 (full scale) = 10Kgs.
ANALOG INPUT (Card 1 Channel 1)
Software (I/P) Multimeter(O/P) : 1% error
21000 (75%) 16.0007mA
28480(100%) 20.0009mA
Software (I/P) Multimeter(O/P)
8mA 25%

35. FUNCTIONAL CHECK of PANEL (Force check)
ANALOG INPUT (Card 2 Channel1)
ANALOG INPUT (Card 3 Channel 1)
The I/O counts vary when the window reopens.
The DIs are potential free (dry connection), i.e. they carry only signal and no
potential to the field instruments. The terminal blocks were also for continuity
with help of a multimeter.
Multimeter(I/P) Software (O/P)
12mA 4252
16mA 21366
Multimeter(I/P) Software (O/P)
12mA 4249
16mA 21370

36. FUNCTIONAL CHECK of PANEL (Force check)
DIGITAL OUTPUT (Card 3 Channel 1)
DIGITAL INPUT
The fused terminal blocks on the panel sides are odd numbered and the
unfused ones are even numbered.
Software (I/P) Multimeter(O/P) : 1% error
True 23.94V
False 0V
Multimeter(I/P) Software (O/P)
NO True
NC False

37. FUNCTIONAL CHECK of PANEL (Force check)
EXPLANATION OF TYPICAL SIGNAL WIRING

38. THANK YOU