Page 1 of 56
Instrumentation NCCER ALL 350 QUESTIONS
AND VERIFIED SOLUTIONS LATEST UPDATE
THIS YEAR
QUESTION: What is the final step in commissioning; what should be the final step? - ANSWER-
gathering all the documentation
QUESTION: In reference to PID controller, reset relates to which variable? - ANSWER-reset or
integral provides an output that is proportional to the time integral of the input. Eliminates
offset.
QUESTION: An employee deenergizes a piece of equipment by removing the power plug from
the outlet, if the employees continue to hold the power plug once removed. The employee is
said to have
what type of control over the energy potential? - ANSWER-exclusive control
QUESTION: The output of a thermocouple is expressed in what units? - ANSWER-milli volts (mV)
1
, Page 2 of 56
QUESTION: A differential pressure transmitter mounted on a non-vented tank is used to
measure the _______ of the vessel? - ANSWER-level
QUESTION: When properly calibrated and installed the most accurate primary flow element is
the ________? - ANSWER-venturi tubes
QUESTION: What is the primary disadvantage of a direct operated regulator? - ANSWER-non
adjustable
QUESTION: What is the advantage of a pilot operated regulator? - ANSWER-The pilot regulator
typically includes proportional band adjustments for verifying the sensitivity.
QUESTION: A valve has linear characteristic when __________. - ANSWER-flow rate provided is
proportional to the amount of value lift
When inspecting a regulator control nitrogen pad system on a large storage tank and no
pressure is found what critical item besides a regulator should be checked? - ANSWER-air
supply
2
, Page 3 of 56
QUESTION: What type of service should Teflon paste never be used on? - ANSWER-service
oxygen lines. PTFE materials are not recommended for service on oxygen lines due to their
anaerobic nature.
QUESTION: A What is the principle behind how a solenoid valve opens? - ANSWER-it consists of
a valve body, a magnetic core attached to a valve stem, and a solenoid coil that works of
inductance.
QUESTION: Which of the following gasses should be used to purge tubing and pipe after
cleaning? - ANSWER-nitrogen
QUESTION: What type of input signal does a valve actuator receive from a V/P transducer? -
ANSWER-pneumatic signal
QUESTION: What does it mean to say that the controller is reverse acting? - ANSWER-decreases
the output signal when the measured medium increases
3
, Page 4 of 56
QUESTION: What does it mean to say that a controller is direct acting? - ANSWER-increases its
output signal when the measure medium increases
QUESTION: How does fail open relate to air to close? - ANSWER-without the control medium, it
stays open; to close, the the control medium must be applied
QUESTION: What does the term fail open mean in relation to valve actuators? - ANSWER-
QUESTION: For a temperature of 1500F, what is a common gasket material? - ANSWER-ceramic
gaskets
QUESTION: Any person working near energized equipment during lockout tagout is considered
what type of
employee? - ANSWER-affected employee
QUESTION: What does P&ID's provide? - ANSWER-illustrates the operational layout of a system
including its piping valves, instrumentation and flow of a product
4
Instrumentation NCCER ALL 350 QUESTIONS
AND VERIFIED SOLUTIONS LATEST UPDATE
THIS YEAR
QUESTION: What is the final step in commissioning; what should be the final step? - ANSWER-
gathering all the documentation
QUESTION: In reference to PID controller, reset relates to which variable? - ANSWER-reset or
integral provides an output that is proportional to the time integral of the input. Eliminates
offset.
QUESTION: An employee deenergizes a piece of equipment by removing the power plug from
the outlet, if the employees continue to hold the power plug once removed. The employee is
said to have
what type of control over the energy potential? - ANSWER-exclusive control
QUESTION: The output of a thermocouple is expressed in what units? - ANSWER-milli volts (mV)
1
, Page 2 of 56
QUESTION: A differential pressure transmitter mounted on a non-vented tank is used to
measure the _______ of the vessel? - ANSWER-level
QUESTION: When properly calibrated and installed the most accurate primary flow element is
the ________? - ANSWER-venturi tubes
QUESTION: What is the primary disadvantage of a direct operated regulator? - ANSWER-non
adjustable
QUESTION: What is the advantage of a pilot operated regulator? - ANSWER-The pilot regulator
typically includes proportional band adjustments for verifying the sensitivity.
QUESTION: A valve has linear characteristic when __________. - ANSWER-flow rate provided is
proportional to the amount of value lift
When inspecting a regulator control nitrogen pad system on a large storage tank and no
pressure is found what critical item besides a regulator should be checked? - ANSWER-air
supply
2
, Page 3 of 56
QUESTION: What type of service should Teflon paste never be used on? - ANSWER-service
oxygen lines. PTFE materials are not recommended for service on oxygen lines due to their
anaerobic nature.
QUESTION: A What is the principle behind how a solenoid valve opens? - ANSWER-it consists of
a valve body, a magnetic core attached to a valve stem, and a solenoid coil that works of
inductance.
QUESTION: Which of the following gasses should be used to purge tubing and pipe after
cleaning? - ANSWER-nitrogen
QUESTION: What type of input signal does a valve actuator receive from a V/P transducer? -
ANSWER-pneumatic signal
QUESTION: What does it mean to say that the controller is reverse acting? - ANSWER-decreases
the output signal when the measured medium increases
3
, Page 4 of 56
QUESTION: What does it mean to say that a controller is direct acting? - ANSWER-increases its
output signal when the measure medium increases
QUESTION: How does fail open relate to air to close? - ANSWER-without the control medium, it
stays open; to close, the the control medium must be applied
QUESTION: What does the term fail open mean in relation to valve actuators? - ANSWER-
QUESTION: For a temperature of 1500F, what is a common gasket material? - ANSWER-ceramic
gaskets
QUESTION: Any person working near energized equipment during lockout tagout is considered
what type of
employee? - ANSWER-affected employee
QUESTION: What does P&ID's provide? - ANSWER-illustrates the operational layout of a system
including its piping valves, instrumentation and flow of a product
4
