Free NCCER Instrumentation Technician Knowledge Assessment Practice Questions

Sample Practice Questions

Try these 10 sample questions from the NCCER Instrumentation Technician Knowledge Assessment practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Which project drawing should an instrument technician review for a new field instrument's location and piping instructions?

   1. A. The instrument loop diagram
   2. B. The piping and instrumentation diagram
   3. C. The instrument specification sheet
   4. D. The termination wiring diagram

   Answer: B

   Explanation: Emerson's installation sequence says, "Review P&ID drawings for location and piping instructions." That identifies the P&ID as the project drawing for this check; loop and termination drawings address connections, while the specification sheet records device requirements.

   Reference: Work Processes Guide — Section 2, Wiring Checkout and Loop Check, physical installation step 1

2. 2When choosing a lubricant for an elastomer O-ring, which effect on the seal material should be avoided?

   1. A. Swelling or shrinking the elastomer
   2. B. Reducing friction at assembly
   3. C. Helping the O-ring seat in its groove
   4. D. Leaving a sliding film on the seal

   Answer: A

   Explanation: Parker states, "The lubricant and its additives must not cause swelling or shrinking of the elastomer." Friction reduction and seating are intended effects of a suitable lubricant.

   Reference: Parker O-Ring Handbook — Section 5.2, Assembly grease and lubricants, page 58

3. 3Before shutting down instrument equipment for service, what must the authorized employee know about its hazardous energy?

   1. A. Its type, magnitude, hazards, and means of control
   2. B. Only the voltage printed on the front panel
   3. C. Only the last recorded operating current
   4. D. Only the number of equipment disconnects

   Answer: A

   Explanation: OSHA's energy-control sequence begins with knowledge of "the type and magnitude of the energy, the hazards of the energy to be controlled, and the method or means to control the energy." A single reading or device count does not cover that preparation.

   Reference: OSHA Lockout/Tagout Tutorial: Application of Energy Control — Application of Energy Control / Preparation for shutdown

4. 4A temperature instrument is specified for 68°F. What is the equivalent temperature in °C?

   1. A. 20°C
   2. B. 36°C
   3. C. 68°C
   4. D. 122°C

   Answer: A

   Explanation: NCCER gives "°C = 5/9 (°F - 32)". For 68°F, 5/9 × (68 − 32) = 20°C.

   Reference: Instrumentation Formula Sheet — Temperature Formulas, page 1

5. 5In a differential-pressure flow installation, what does the primary element do?

   1. A. Creates a restriction that produces a pressure drop
   2. B. Measures the pressure drop and outputs a signal
   3. C. Interprets the transmitted current as a flow value
   4. D. Converts a sensor voltage to a digital protocol

   Answer: A

   Explanation: Emerson states, "The primary element creates a pressure drop by introducing a restriction in the flow". The primary element establishes the measurable differential; the transmitter is the secondary element.

   Reference: Differential Pressure Flow Meters — How It Works / DP Flow systems

6. 6What is the main job of a control-valve actuator?

   1. A. Move the valve's closure member in response to a control signal
   2. B. Measure process pressure and transmit a signal
   3. C. Compare the process variable with the setpoint
   4. D. Filter contaminants from the instrument air supply

   Answer: A

   Explanation: Spirax Sarco states, "The actuator accepts a signal from the control system and, in response, moves the valve to a fully-open or fully-closed position, or a more open or a more closed position". That movement is the actuator's role.

   Reference: Control Valve Actuators and Positioners — Actuators

7. 7When laying out successive bends in an instrument tube line, what reference is used for the distance between bends?

   1. A. The tube centerline
   2. B. The outside edge of the tube
   3. C. The inner radius of the first fitting
   4. D. The nut face at the final connection

   Answer: A

   Explanation: Parker states, "The centerline of the tube is the basis for all tube line measurement". The first bend is measured from the tube end, while subsequent bends use centerline geometry.

   Reference: Instrument Tube Fitting Installation Manual — Principles of Tube Line Fabrication / Tube Centerline Basis for Measurement, p.7

8. 8Where should uninstalled instrument tubing be stored to limit moisture, contamination and damage?

   1. A. Indoors, off the floor, on racks
   2. B. Outdoors directly on the ground
   3. C. In contact with process piping
   4. D. Loose beneath a workbench

   Answer: A

   Explanation: Parker states, "Tube should be stored inside, off the floor, on racks to remove all these potential issues." The issues listed include water, contamination, corrosion and scratches.

   Reference: 10 Steps to Cost Effective & Safe Installation of Instrumentation Tube and Fittings Systems — Step 8 – Material Storage

9. 9A Rosemount 3051 transmitter's analog output must map a new pressure range to 4 and 20 mA without altering sensor calibration. Which operation is appropriate?

   1. A. Reranging
   2. B. Sensor trim
   3. C. Analog output trim
   4. D. Grounding the shield

   Answer: A

   Explanation: Emerson defines "Reranging: Setting the lower and upper range points (4 and 20 mA or 1 and 5 Vdc) points at required pressures. Reranging does not change the factory sensor characterization curve." This sets the output endpoints for the new pressure range without altering sensor characterization.

   Reference: Rosemount 3051 Pressure Transmitter Reference Manual — Calibration overview / reranging, p.67

10. 10For a frequency reading with a Fluke 381, what should be centered around the measurement source?

    1. A. Clamp jaw or flexible current probe
    2. B. Voltage probes across the supply
    3. C. Resistance leads across the load
    4. D. Capacitance probes across the sensor

    Answer: A

    Explanation: Fluke instructs, "Center the jaw or flexible probe around the measurement source." The clamp jaw or flexible probe surrounds the source for this Hz measurement; contact probes are used for other functions.

    Reference: How to Measure Signals Using Test Probes — How to measure signals using test probes / To measure frequency (on the Fluke 381)