Instrumentation Engineering Interview Questions and Answers
Question - 31 : - What are the different types of Bourdon tubes?
Answer - 31 : -
Question - 32 : - State the principle of LVDT
Answer - 32 : -
The LVDT’s secondary winding differential output voltage is proportional to the displacement felt by the mass induced by the Core acceleration; the differential output voltage becomes an acceleration metric.
Question - 33 : - State the principle of Mc leod gauge
Answer - 33 : -
Compression of a low-pressure gas sample to a point that is high enough to be read using a simple manometer.
Question - 34 : - What is the force balance principle?
Answer - 34 : -
Principle of force balance: a controller that produces a torque-opposed output signal. The input force is applied to the beam moving reference bellows. This breaks the backpressure of the nozzle.
The backpressure of the nozzle is felt by the rotating bellows that support the projector. The baffle movement for full-scale output is much less than 0.002.
Question - 35 : - What is motion balance principle?
Answer - 35 : -
A controller that moves its parts to generate an output signal. Moving towards the nozzle is the increase in the baffle. The backpressure of the nozzle is going to increase.
The bellows will extend this change in the backpressure acting on the balancing bellows. As a consequence, the nozzle is pushed upwards. The nozzle moves until movement is almost equal to the movement of the input baffle.
Question - 36 : - What is the difference between differential pressure and Delta pressure?
Answer - 36 : -
Differential pressure means the difference between high pressure & low pressure. Delta Pressure stands for the difference between two measured pressure values. This can be measured either at different times/dates or at different positions in a system.
Question - 37 : - How DP transmitter can be applied to open tank?
Answer - 37 : -
The lower pressure side is released into the atmosphere in the open tank. All the pressure is applied to the hand of the high pressure. The pressure of this vessel is determined by the side of the high pressure.
Question - 38 : - What is a P&ID?
Answer - 38 : -
Piping and Instrumentation Diagrams (P&ID) are schemes of pipelines, equipment, instrumentation, control systems, from a process system found in Oil Refinery, Chemical Plant, Paper Mill, Cement Plant, etc.
Question - 39 : - Why to use P&ID?
Answer - 39 : -
To describe all plant and equipment. This indicates the flows in a plant and the sensors or other devices in question. It gives names and parameters to each sensor and other equipment.
It is a pictorial image of the processing facilities:
- Key piping and instrument details
- Control and shutdown schemes
- Safety and regulatory requirements
- Basic start up and operational information
Question - 40 : - What are the items that will listed in a P&ID?
Answer - 40 : -
- Instrumentation and designations
- Mechanical equipment with names and numbers
- All valves and their identifications
- Process piping, sizes and identification
- Miscellanea – vents, drains, special fittings, sampling lines, reducers, increasers and swaggers
- Permanent start-up and flush lines
- Flow directions
- Interconnections references
- Control inputs and outputs, interlocks
- Interfaces for class changes
- Computer control system
- Identification of components and subsystems