1. Instrumentation Malfunctions, Test Review - Agenda
Activity
Estimated Time
1. Agenda 5
2. Learning Objectives
3. Identifying Instrument Malfunction 50
BREAK 10
4. Instrumentation Failure Modes
5. Loop Response to Instrumentation Failure 30
6. Matching Activity
7. Summary and Wrap-Up
8. Additional Activities
9. Lab Activity
Slide 1
Instrumentation 2 – Session 15

2. Session Objectives
Recall the methods used for determining if a sensing/measuring device is malfunctioning:
remote vs. local indication.
Describe the failure modes of the following:
temperature elements
thermocouples
RTDs
level floats
flow elements
pressure elements
analytical elements
Explain how a control loop will respond to typical malfunctions in the following:
primary sensing elements
transmitters
controllers
final control elements.
Slide 2
Instrumentation 2 – Session 15

3. Process of Elimination
Slide 3
Instrumentation 2 – Session 15

4. Abrupt Indication Change
Slide 4
Instrumentation 2 – Session 15

5. Gradual Deterioration
Slide 5
Instrumentation 2 – Session 15

6. Fixed Deviation
Slide 6
Instrumentation 2 – Session 15

7. Calibration
Slide 7
Instrumentation 2 – Session 15

8. RTD Failure
Slide 8
Instrumentation 2 – Session 15

9. Orifice Meter
Slide 9
Instrumentation 2 – Session 15

10. Analyzer
Slide 10
Instrumentation 2 – Session 15

11. Loop Response
Slide 11
Instrumentation 2 – Session 15

12. Match From the List gradual deviation
fixed deviation
a noisy signal
automatic reset
Loose signal wire connections are most likely to cause
Slide 12
Instrumentation 2 – Session 15

13. Match From the List gradual deviation
fixed deviation
a noisy signal
automatic reset
Loose signal wire connections are most likely to cause
Slide 13
Instrumentation 2 – Session 15

14. True - False
True
False
Instrument error that increases gradually is more difficult to detect.
Slide 14
Instrumentation 2 – Session 15

15. True - False
True
False
Instrument error that increases gradually is more difficult to detect.
Slide 15
Instrumentation 2 – Session 15

16. Match From the List pressure
flow
temperature
level
It is most practical to calibrate instruments that measure
Slide 16
Instrumentation 2 – Session 15

17. Match From the List pressure
flow
temperature
level
It is most practical to calibrate instruments that measure
Slide 17
Instrumentation 2 – Session 15

18. Match From the List a jump in the output signal
a drop in the output signal
a zero output signal
a gradual drop in the output signal
A shorted wire in an rtd will result in
Slide 18
Instrumentation 2 – Session 15

19. Match From the List a jump in the output signal
a drop in the output signal
a zero output signal
a gradual drop in the output signal
A shorted wire in an RTD will result in
Slide 19
Instrumentation 2 – Session 15

20. True - False True A controller will likely detect a fixed deviation
Slide 20
Instrumentation 2 – Session 15

21. True - False True A controller will likely detect a fixed deviation
Slide 21
Instrumentation 2 – Session 15

22. Match From the List a plugged (lp) leg
an open equalizer valve
none of the above
a plugged (hp) leg
A steep rise in flow indication from an orifice meter would likely be cause by:
Slide 22
Instrumentation 2 – Session 15

23. Match From the List a plugged (lp) leg
an open equalizer valve
a plugged (hp) leg
none of the above
A steep rise in flow indication from an orifice meter would likely be cause by:
Slide 23
Instrumentation 2 – Session 15

24. True - False
True
False
Thermocouples may deteriorate due to improper environment
Slide 24
Instrumentation 2 – Session 15

25. True - False
True
False
Thermocouples may deteriorate due to improper environment
Slide 25
Instrumentation 2 – Session 15

26. Match From the List calibrate weekly
change filters at regular intervals
add water to the guard bed regularly
add flux to all test samples
A precaution to avoid analyzer failure
Slide 26
Instrumentation 2 – Session 15

27. Match From the List calibrate weekly
change filters at regular intervals
add water to the guard bed regularly
add flux to all test samples
A precaution to avoid analyzer failure
Slide 27
Instrumentation 2 – Session 15