SAMPLE PAPER OF INDUSTRIAL INSTRUMENTATION FOR ELECTRONIC AND COMMUNICATION
TIME: 3 HRS.
NOTE: All the questions of section-a is compulsory and any 5 from the section-b.
Short questions: (each 2 marks)
1. Define an instrument. What is the purpose of instrumentation?
ans: Instrument is a device used for the direct or indirect measurement of different process variables. The purpose of instrumentation in a process is to obtain the necessary information required for faithful completion of process.
2. What is process Variable? Explain with examples?
ans: The parameters included in the entire process is known as process variable.
3. Differentiate between Active and Passive types of instrument with examples?
ans: Active instruments modulates the magnitude of some external power source.Passive instruments output is produces only due to the measured quantity.
4. What are null types of instrument mainly used for and why?
ans: In this type a zero or null indication leads to the determination of the magnitude of measured quantity.
5. What is a Smart instrument? Cite two example of Smart instrument.
ans: The smart instruments incorporate with microprocessor to perform almost all signal processing or information processing.
6. Define Range of an instrument.
ans: The range of an instrument is defined as the largest and the smallest reading either in its input or output.
7. What do you mean by calibration? And why it is necessary.
ans: It is a procedure that involves a comparison of a particular instrument with either a primary standard or a secondary standard with higher accuracy or a known output source.
8. Distinguish between accuracy and precession.
ans: Accuracy is defined as the degree of closeness of the measured value towards the free value.
9. What do you mean by nonlinearity of an instrument?
ans: The non- linearity is defined as the maximum deviation of any output reading from the straight line.
10. What is resolution of an instrument?
ans: The resolution of an instrument defines the smallest in measured quantity that can be observed.
LONG QUESTIONS: (each 10 marks)
1. Draw the schematic diagram of telemetry system
2. Explain any five types of Instruments with examples?
ans: Absolute instruments:: It gives the magnitude of measured quantity in terms of some physical constants of instruments.
Secondary instruments : These are so constructed that the measured quantity can only be determined by observing the output indicated by the instrument.
Deflection type instruments: In this type the deflection of the instrument provides a basis for determining the quantity under measurement.
Null type: In this type a zero or null indication leads to the determination of the magnitude of measured quantity.
Active instruments: In this case of active instruments the quantity to be measured is simply modulates the magnitude of some external power source.
3. Explain any five static characteristics of an Instrument?
ans: Range: The ranges of an instrument is defined as the largest and the smallest reading either in its o/p or i/p
Span:: It is the maximum variation in i/p or in o/p
Accuracy:: It is defined as the degree of closeness of the measured value towards the true value.
Caliberation: It is a procedure that involves a comparison of a particular instrument with either a primary standard or a secondary standard with higher accuracy or a known o/p source.
Resolution: : the resolution of an instrument defines the smallest change in measued quantity that can be observed.
4. Write down the different errors ?
ans: Interference error: Any error that arises due to different effects produced in the measuring circuit like electromagnetic interference, is called interference error.
Operational error: These types of error occcurs due to any change in operating conditions like method of measurement ambient temp and pressure etc.
Installation error: The error result due to the improper installation of primary element of the measurement system is called installation error
Equipment error: When the measured value is equipment dependent then any change in measurement o/p dependent then any change in measurement o/p causing an error called equipment error.
Loading error:The error also arise in measurement system because of lading of receiving unit by subseding unit.
5. Draw the schematic diagram of TDM.