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NCCER REVIEW EXAM questions and
answers 2026 \ 2027 update
A technology bypassing conventional I/O by using direct communications between smart field devices and associated control processors is: SCADA WAN Peer-to-peer Fieldbus correct answers : Fieldbus In a test of the accuracy of a pneumatic comparator with a pressure gauge, pressure readings of the test gauge and the gauge being tested are compared at a number of test points. Test points readings are made: Only as the pressure is slowly increased Only as the pressure is slowly decreased In no particular sequence As the pressure is both increased and decreased correct answers : As the pressure is both increased and decreased Mass flow measurement requires accurate values is: Volumetric flow Temperature Pressure All of the above correct answers : All of the above When a sensor is inserted in a thermowell, which of the following could safely improve response to temperature changes? Mercury
Antifreeze Copper strips Magnesium oxide particles correct answers : Antifreeze What type of transducer converts the variable being measured into a voltage generated by a crystal when it is mechanically stressed? Reluctive Piezoelectric (used in DP cells) Inductive Capacitive correct answers : Piezoelectric (used in DP cells) A gage pressure of 195 psi is roughly what in psia? 151 164 178 210 correct answers : 195 + 14.7=210 at sea level Which comment below does NOT describe a force-balance transmitter? Is self-balancing Output signal is proportional to process variable signal Operates with a thrust rod Has a force beam that pivots on a fulcrum correct answers : Operates with a thrust rod Changing the proportional band of a pneumatic controller changes:
Which of the following provides a warning when low and/or high limits of optimum range are being approached? Calibrating trim pots Absolute alarm points Variable set points Range adjusters correct answers : Absolute alarm points A device that converts alternating current to direct current is called a: Rectifier Ratio station Differential amplifier Comparator correct answers : Rectifier The oil within the variable capacitor of a capacitance-type differential pressure transmitter is separated from the process by: A sensing diaphragm Capacitor plates Isolating diaphragms Bellows correct answers : A sensing diaphragm When a dip pipe (bubbler) system is used for tank level measurement, the dip pipe is connected to: The purge gas flow controller The low side of the dP cell The high side of the dP cell The dP cell output signal line correct answers : The purge gas flow controller
A logic gate most similar to a parallel circuit is the: AND gate NOT gate OR gate NAND gate correct answers : OR gate Differential pressure transmitters measure level by inference from: Capacitance Conductivity Hydrostatic head Thermal energy correct answers : Hydrostatic head Which of the following types of control has the most offset: Proportional Proportional-plus-reset On-off Proportional-plus-reset-plus-rate correct answers : On-off Hydrostatic head level can NOT be measured with a: dP cell Dip pipe Resistance probe Pressure gage correct answers : Resistance probe
Venturi tube Dall flow tube correct answers : Thermistor What occurs if the temperature of the thermocouple measuring junction is lower than the reference junction? There is no emf output The output voltage polarity is reversed The polarity stays the same but voltage increases The emf remains the same when temperature changes correct answers : The output voltage polarity is reversed Which of the following temperature sensors produces an output resistance directly related to the temperature of the device? Thermocouple RTD Thermistor Both B and C correct answers : RTD Name a direct method of measuring level Sight glass Dip stick Float and cable All of the above correct answers : All of the above If the range of a 3-15 psi pneumatic transmitter is 50-350 degrees F, what is the output signal value at 198 degrees F?
5.7 psi 7.2 psi 8.9 psi 12.6 psi correct answers : 8.9 psi Limit switch cams are usually found in: Solenoid actuators Diaphragm actuator Piston actuators Electric motor actuators correct answers : Electric motor actuators Which of the following is NOT a characteristic of positioners? Slow down response Minimize friction effects Permit split-range valve operation Allow for biasing the valve correct answers : Allow for biasing the valve Which of the following types of actuators responds to a pneumatic signal? Diaphragm Motor Solenoid Electromagnetic valve correct answers : Diaphragm In which action does increasing signal pressure cause the actuator stem to move upward, closing a valve? Direct action, air-to-close
If a controller does not have full output when the manual adjustment is rotated to move the output pressure to full scale, the LEAST likely source of the problem would be: Low supply air pressure Proportional band setting Clogged filters
Leaks in the output signal line correct answers : Proportional band setting If nozzle backpressure does not decrease when it should, the most likely cause is: Faulty process input signal Dirt buildup on the flapper Nozzle clogged with dirt High supply air pressure correct answers : Nozzle clogged with dirt Input to the _______ bellows flows through an adjustable restriction. Reset Measurement Set point Proportional correct answers : Reset For alignment of a proportional band of a controller changes: Maximum 30% 70% Minimum correct answers : Maximum Changing the proportional band of a controller changes: The alignment of the controller The position of the nozzle to the baffle The gain The set point correct answers : The alignment of the controller
Grounding the shield at two points with different voltage potentials correct answers : Grounding the shield at only one end of the circuit A low resistance reading from an ungrounded signal lead connected to ground indicates a problem of: A lead having an unwanted connection to ground An open circuit from the lead to ground An open circuit from the lead to the casing None of the above correct answers : A lead having an unwanted connection to ground 75% output on a 4-20 milliamp transmitter is: 12 milliamps 15 milliamps 16 milliamps 20 milliamps correct answers : 16 milliamps What is used to change a 3-15 psi to 4-20 mA? P/I transducer E/I transducer I/P transducer mV/I transduce correct answers : P/I transducer Which of the following can provide input/output isolation? Optical coupling A successive approximation converter Optical coupling A dual-slope integrator converter
Clock-circuits correct answers : Optical coupling A multi-conductor cable printed circuit board with multiple conductive tracks is called: A register Ladder logic A bus A sequential adder circuit correct answers : A bus The decimal equivalent of 10011 binary is: 3 12 19 21 correct answers : 19 The term used to describe multiple lines sending eight bits of data at a time is: Parallel transmission Interface Serial transmission Protocol correct answers : Serial transmission An oscilloscope waveform spans 5.5 vertical divisions. The vertical gain control is set at 2 volts/division/ the peak-to-peak voltage of the signal on the oscilloscope is: 33 volts 22 volts 11 volts
c. Number of bolts used d. Grade of bolt correct answers : d. Grade of bolt What does the "PI" in PI-209 stand for? a. Pressure Indicator. b. Pneumatic Indicator. c. Pressure Index. d. Pressure Isolator. correct answers : a. Pressure Indicator. Line markings on the heads of bolts and screws indicate: a. threads per inch. b. possible turns for tightening. c. ,grade. d. manufacturer correct answers : c. grade Which of the following materials is selected when a resistance to corrosion or high temperatures is required? a. High-carbon steel b. Low-carbon steel c. Nickel Alloy d. Nonferrous alloy correct answers : d. Nonferrous alloy The letters "EL" on a blueprint stand for a. elevator. b. elevation. c. electricity.
d. end of line correct answers : b. elevation Before performing a continuity check on a circuit, the instrument technician MUST be sure that the circuit is a. energized. b. de-energized. c. properly routed. d. grounded correct answers : b. de-energized A chemical, classified as a base, harms a human body by causing all the following EXCEPT: a. severe respiratory burns b. dissolved skin tissue c. irritation to nose and throat membranes d. calcification of the tongue correct answers : d. calcification of the tongue A system installed to provide protection of equipment from line-to-ground fault damage is called a. a ground-fault circuit interrupter. b. an Uninterruptible Power Supply (UPS). c. a ground-fault transformer. d. a distance relay. correct answers : a. a ground-fault circuit interrupter. A confined space is identified as: a. having limited entry and exit b. having more people than the occupancy rating.
Color properties of oxygen Dissolvability of oxygen in water Liquefaction properties of oxygen Paramagnetic properties of oxygen correct answers : Color properties of oxygen A Piece of pipe has an AISI classification of A105, the major alloy is: Carbon Nickel Nickel-Chrome Chrome-Vanadium correct answers : Carbon Atmosphere testing must be conducted before entry into a confined space to check for: Humidity level Heat level Oxygen content MSDS content correct answers : Oxygen content Which of the following contains information about chemicals found on a job site? Chemical Exposure Sheet Material Safety Data Sheet Manufactured Substance Data Sheet Hazardous Exposure Sheet correct answers : Material Safety Data Sheet
Which of the following materials is selected when resistance to corrosion or high temperatures is required? High-carbon steel Low-carbon steel Nickel Alloy Nonferrous Alloy correct answers : Nonferrous Alloy Which of the following is a type of gasket used in high-pressure systems? Teflon Fiberglass Asbestos Metal ring joint correct answers : Metal Ring Joint Examples of inactive cutting oil include all of the following EXCEPT: Straight mineral oils Fatty and mineral oil blends Sulfurized mineral oils Fatty oils correct answers : Sulfurized mineral oils Which of the following thread sealant is MOST suitable for service temperatures of 500 to 700 degrees Fahrenheit? High-temperature epoxy Teflon paste High-temperature RTV silicone Graphite paste correct answers : Graphite paste
