Instrumentation Questions List

Interview Questions Instrumentation
1

Top 30 Instrumentation Questions List for your reference.

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Instrumentation Questions

  1. How can level control be installed in steam drum for measuring the level of steam drum?
  2. What is ultrasonic flowmeter?
  3. Differentiate between ultrasonic flowmeter and radar type flow meter.
  4. What is the use of temperature compensation?
  5. What is modbus?
  6. How signals can be taken through modbus?
  7. How earthing can be checked?
  8. How many ohms are required for proper earthing?
  9. Explain signal isolator.
  10. Which wiring connection is preferred in motor for industrial use?
  11. What do you mean by trim?
  12. How DP Transmitter can be calibrated for crude application in floating roof tank?
  13. What is the principle of capacitance type level transmitter?
  14. How process line mpm calculation is done?
  15. Explain PLC and its types?
  16. What is procedure on mmwc in to tph?
  17. How an RTD work, and what volts/current goes to a RTD to measure the resistance?
  18. What is consistency transmitter and describe its working?
  19. How to calculate MMWC values into tonnes?
  20. How can I make calculation to Install level transmitter (DP) for open tank and close tank?
  21. What is difference between DO and DI?
  22. What is loop1 and loop2 in MTS LT?
  23. How to calibration a control valve?
  24. What is dry leg calibration and where is it used?
  25. How flow can be measured with DP?
  26. Why MMWC unit is used?
  27. How HART protocol can be connected with control valves?
  28. What is the meaning of slope in PH transmitter?
  29. What is Difference between PLC, DCS and CNC?
  30. If we have 450 mm height boiler drum level, so what is span & zero value for a dpt transmitter?
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What is difference between DO and DI?

DO- Digital output
DI- Digital Input

DI- Basically a kind of status signals we receive from field instruments to control systems Status such as ‘0’ or ‘1’

(Example : Pressure switch contact (NO/NC) - NO=0, NC= 1, Push button status from a local control panel (Pump Start PB, Pump Stop PB)

These status signals are required basically to understand the current status of the plant/equipment/process etc.

DO- Digital output is signal which is given to field final control elements such as (solenoid valves, dampers, switch gear, motorized valves etc) to perform certain action.

DO signals shall be configured as 0 or 1, when the logic gives 0 then the voltage at the marshalling rack will be 0 V, when the logic state is 1 then the voltage across the terminals will be 24V based on the designed hardware. This voltage is used to directly energize the solenoid, or used to energize the relay to change the contacts (Open/close contacts) of a circult.

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