Instrumentation Technician Level II
Exam Practice Questions And Correct
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1. An instrumentation technician is calibrating a pressure transmitter
with a 4–20 mA output. The input pressure range is 0–100 psi. During
calibration, the technician applies 50 psi. What output current should
be observed if the transmitter is functioning correctly?
A. 8 mA
B. 12 mA
C. 16 mA
D. 10 mA
At 50% of the pressure span (50 psi out of 100 psi), the transmitter
, output should also be at 50% of the current span, which is 12 mA
between 4 mA and 20 mA.
2. A temperature transmitter uses a thermocouple input. Which principle
best describes how a thermocouple generates a signal?
A. Resistance change due to temperature
B. Inductive coupling between metals
C. Seebeck effect producing a voltage from temperature difference
D. Piezoelectric crystal deformation
A thermocouple operates based on the Seebeck effect, where a
voltage is generated when two dissimilar metals experience a
temperature difference.
3. In a closed-loop control system, what is the primary purpose of the
controller?
A. Measure the process variable
B. Adjust the final control element based on feedback
C. Compare setpoint and process variable and generate corrective
action
D. Eliminate sensor drift
The controller continuously compares the setpoint with the measured
process variable and adjusts the output to minimize error.
4. Which device is most commonly used as a final control element in a
flow control loop?
A. Pressure transmitter
, B. Flow switch
C. Control valve
D. Signal conditioner
A control valve regulates flow by adjusting its opening in response to
controller output.
5. What is the primary function of a differential pressure transmitter in
flow measurement?
A. Measure fluid density directly
B. Convert velocity into voltage
C. Determine flow rate by measuring pressure drop across an
element
D. Measure temperature gradient
Differential pressure transmitters infer flow rate by measuring
pressure difference across restrictions like orifice plates.
6. Which signal standard is most commonly used in industrial
instrumentation for analog communication?
A. 0–10 V DC
B. 1–5 V DC
C. 4–20 mA DC
D. 0–24 mA DC
The 4–20 mA standard is widely used due to its noise immunity and
ability to detect wire breaks.
, 7. A PLC scan cycle includes which of the following steps?
A. Output update, programming, diagnostics, input scan
B. Input scan, program execution, output update, housekeeping
C. Programming, compilation, execution, shutdown
D. Input calibration, logic verification, output shutdown
A PLC sequentially reads inputs, executes logic, updates outputs, and
performs internal housekeeping each scan cycle.
8. What is the purpose of a PID controller’s integral action?
A. Reduce overshoot
B. Increase system stability margin
C. Eliminate steady-state error
D. Increase system gain
Integral action accumulates error over time to eliminate steady-state
offset.
9. Which instrument is best suited for measuring very low pressure
differences in clean rooms?
A. Bourdon tube gauge
B. Manometer
C. Diaphragm pressure transmitter
D. Strain gauge load cell
Diaphragm-based transmitters are highly sensitive and suitable for
low differential pressures.
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. An instrumentation technician is calibrating a pressure transmitter
with a 4–20 mA output. The input pressure range is 0–100 psi. During
calibration, the technician applies 50 psi. What output current should
be observed if the transmitter is functioning correctly?
A. 8 mA
B. 12 mA
C. 16 mA
D. 10 mA
At 50% of the pressure span (50 psi out of 100 psi), the transmitter
, output should also be at 50% of the current span, which is 12 mA
between 4 mA and 20 mA.
2. A temperature transmitter uses a thermocouple input. Which principle
best describes how a thermocouple generates a signal?
A. Resistance change due to temperature
B. Inductive coupling between metals
C. Seebeck effect producing a voltage from temperature difference
D. Piezoelectric crystal deformation
A thermocouple operates based on the Seebeck effect, where a
voltage is generated when two dissimilar metals experience a
temperature difference.
3. In a closed-loop control system, what is the primary purpose of the
controller?
A. Measure the process variable
B. Adjust the final control element based on feedback
C. Compare setpoint and process variable and generate corrective
action
D. Eliminate sensor drift
The controller continuously compares the setpoint with the measured
process variable and adjusts the output to minimize error.
4. Which device is most commonly used as a final control element in a
flow control loop?
A. Pressure transmitter
, B. Flow switch
C. Control valve
D. Signal conditioner
A control valve regulates flow by adjusting its opening in response to
controller output.
5. What is the primary function of a differential pressure transmitter in
flow measurement?
A. Measure fluid density directly
B. Convert velocity into voltage
C. Determine flow rate by measuring pressure drop across an
element
D. Measure temperature gradient
Differential pressure transmitters infer flow rate by measuring
pressure difference across restrictions like orifice plates.
6. Which signal standard is most commonly used in industrial
instrumentation for analog communication?
A. 0–10 V DC
B. 1–5 V DC
C. 4–20 mA DC
D. 0–24 mA DC
The 4–20 mA standard is widely used due to its noise immunity and
ability to detect wire breaks.
, 7. A PLC scan cycle includes which of the following steps?
A. Output update, programming, diagnostics, input scan
B. Input scan, program execution, output update, housekeeping
C. Programming, compilation, execution, shutdown
D. Input calibration, logic verification, output shutdown
A PLC sequentially reads inputs, executes logic, updates outputs, and
performs internal housekeeping each scan cycle.
8. What is the purpose of a PID controller’s integral action?
A. Reduce overshoot
B. Increase system stability margin
C. Eliminate steady-state error
D. Increase system gain
Integral action accumulates error over time to eliminate steady-state
offset.
9. Which instrument is best suited for measuring very low pressure
differences in clean rooms?
A. Bourdon tube gauge
B. Manometer
C. Diaphragm pressure transmitter
D. Strain gauge load cell
Diaphragm-based transmitters are highly sensitive and suitable for
low differential pressures.
