Domain 1 Flashcards
- When troubleshooting a 4-20 mA transmitter, you discover the transmitter is powering off at 100% output. What is the most likely cause?
A. Too much resistance in the loop
B. Too little resistance in the loop
C. Excessive current in the loop
D. Excessive voltage in the loop
A. Too much resistance in the loop.
- Good manufacturing practice recommends that a test instrument be _________ times more accurate than the unit under test.
A. 2
B. 4
C. 6
D. 8
B. 4
- The statement: “thermocouple extension wires must have the same thermoelectric properties as the thermocouple that they are used with,” is:
A. True if the extension wires are submerged in the process fluid.
B. True in most installations
C. False. Extension wires must be made from copper or brass.
D. False. The type of extension wire makes no difference.
B. True in most installations.
- If a current of 9 mA is flowing through a 250 ohm resistor, what would be the voltage drop across the resistor?
A. 12.5 V
B. 22.5 V
C. .225 V
D. 2.25 V
D. 2.25 V
- What is the preferred orientation to use when installing a magnetic flowmeter?
A. Vertical, downward flow
B. Horizontal, upward flow
C. Vertical, upward flow
D. Horizontal, downward flow
C. Vertical, upward flow
- What pressure, in PSI, would be indicated by a properly calibrated absolute pressure gauge that is lying on the workbench at sea level not connected to anything?
A. 0
B. 29
C. 14.7
D. 2.9
C. 14.7
- A gauge pressure of 195 PSI is roughly what in PSIA?
A. 151
B. 164
C. 178
D. 210
D. 210
- Which of the following will have the highest pressure difference between the surface and 6 inches below the surface?
A. 12 inch vertical straw filled with water
B. A 10 foot diameter open tank filled with water
C. A 5 foot diameter vertical pipe filled with water
D. None of the above, because the pressure difference in each is the same
D. None of the above, because the pressure difference in each is the same
- Hydrostatic head is another way of expressing:
A. Gallons
B. Pressure
C. Length
D. Mass
B. Pressure
- Dividing the density of the process fluid by the density of ______ gives a dimensionless number called specific gravity.
A. Mercury or mercury vapors
B. Oil or natural gas
C. Water or air
D. Any known liquid or gas
C. Water or air
- As the speed (velocity) of a fluid increases through a restriction, the fluid pressure downstream
A. Increases
B. Decreases
C. Remains unchanged
D. First increases then decreases
D. Decreases
- What Celsius temperature reading is within an oven temperature of 215 to 220 deg. C?
A. 103
B. 110
C. 329
D. 338
A. 103
- The difference between the indication of the instrument and the actual value of the measured variable is:
A. The controlled variable
B. Called setpoint
C. An error in the measuring instrument
D. Discarded
C. An error in the measuring instrument
- Hydrostatic head, weight, radioactive properties, density, and sonic detectors are all used in which methods of level measurement?
A. Point
B. Pressure
C. Inferential
D. Direct
C. Inferential
- Differential pressure transmitters measure level by inference from:
A. Capacitance
B. Conductivity
C. Hydrostatic head
D. Thermal energy
C. Hydrostatic head
- Thermal elements infer level by measuring:
A. Temperature
B. Capacitance
C. Thermal conductivity
D. Displacement
A. Temperature
- All of the following types of level instruments can be used to detect the location of liquid services except:
A. Radar
B. Float
C. Hydrostatic head
D. Ultrasonic
C. Hydrostatic head
- The temperature range of a transmitter is 100 to 200°F. The output signal range is 3 to 15 psig. What would be the expected output signal for an input temperature of 150°F?
A. 6 psig
B. 9 psig
C. 11.25 psig
D. 12 psig
B. 9 psig
- 75% output on a 4 to 20 mA transmitter is:
A. 12 mA
B. 15 mA
C. 16 mA
D. 20 mA
C. 16 mA
- What is the designation used for a transducer that converts current to voltage?
A. E / I
B. I / P
C. P / I
D. I / E
D. I / E
- An instrument gives the same indication each time it measures a variable under identical conditions. This defines:
A. Static accuracy
B. Dynamic accuracy
C. Sensitivity
D. Repeatability
D. Repeatability
- The range of values over which an input signal to a transmitter may be changed upon reversal of direction with no observable change in input is called:
A. Instrument accuracy
B. Reverse precision
C. Zero point
D. Dead band
D. Dead band