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
- The steady-state gain of a standard 4-20 mA electronic hydrostatic head level transmitter with a measurement range of 50-250 inches of water is:
A. 0.08 mA / inch of water
B. 0.10 mA/inch of water
C. 16 mA/200 inches of water
D. 20 mA/250 inches of water
A. 0.08 mA/inch of water
- The temperature range of a transmitter is 0 to 200°F. The output signal range is 3 to 15 psig. What would be the expected output signal for input temperature of 150°F?
A. 6 psig
B. 9 psig
C. 11.25 psig
D. 12 psig
D. 12 psig
- Using ANSI / ISA standards, the red lead from thermocouple or extension wire is always the _________ lead.
A. Positive
B. Negative
C. Neutral
D. Ground
B. Negative
- An instrument measurement error is the difference between the actual value of the measured variable and:
A. It’s true value
B. The calibration standard
C. Input and output signals
D. The indication of the instrument
D. The indication of the instrument
- To ensure the accuracy of the pneumatic controller throughout its range, you must precisely adjust all the following except:
A. Supply pressure
B. Input
C. Span
D. Zero
A. Supply pressure
- A device that converts alternating current to direct current is called a:
A. Rectifier
B. Radio station
C. Differential amplifier
D. Comparator
A. Rectifier
- A test instrument that displays the waveform is a(n):
A. Function generator
B. Ammeter
C. Multimeter
D. Oscilloscope
D. Oscilloscope
- What is the measurement in KPa of the pressure transmitter that is reading 20 PSI?
A. 137.9 KPa
B. 13.79 KPa
C. 40.7 KPa
D. 4.07 KPa
A. 137.9 KPa
- Which of the following could be used to calibrate a pressure gauge that is 0 to 800 PSI?
A. Dead-weight tester
B. A Mercury manometer
C. The plant instrument air supply
D. Multimeter
A. Dead weight tester
- 2 psi is equal to ________ inches of water.
A. 1
B. 27.7
C. 14.7
D. 55.4
D. 55.4
- Which of the following is usually adjusted first when calibrating an electronic pressure transmitter?
A. Linearity
B. Span
C. Zero
D. Range
C. Zero
- The calibration plot below shows that the transmitter does need recalibration to correct for:
A. A zero error
B. A span error
C. Both a zero and span error
D. A linearity error
A. A zero error
- The calibration plot below indicates that the pneumatic controller has __________ and must be calibrated.
A. A zero error
B. A span error
C. Both a zero and a span error
D. A linearity error
C. Both a zero and a span error
- __________ is a relative measurement of the time delay between two events, states, or actions.
A. Backlash
B. Dead time
C. Hysteresis
D. Dead band
B. Dead time
- The Reynolds No. determines:
A. The Venturi effect
B. The coriolis acceleration
C. The fluid viscosity
D. If the flow is laminar or turbulent
C. The fluid viscosity
- The flow rate in gpm of water with a specific gravity of 1 provided by a pressure differential of 1.0 psi through a fully opened control valve is a definition of:
A. Cv
B. DP
C. Ov
D. SG
A. Cv
- A plant has a 30 foot high water mounted on top of a 70 foot platform. What is the water level in the tank, measured in feet, if the pressure gauge on the first floor, height 5 feet, reads 40 psi?
A. 22.3
B. 27.3
C. 30
D. 10
B. 27.3
- The 0 to 30 psig gauge is being calibrated. Starting at 0 psi, the technician applies pressure of 15 psi. The gauge reads 14.9 PSI. Then the technician applies 30 PSI. When the pressure is reduced to 15 psi, the reading is 15.2 psi G. What type of error might these readings indicate?
A. Hysterics error
B. Span error
C. Zero shift error
D. Linearity error
A. Hysteresis error
- If the range of a 3 to 15 psi pneumatic transmitter is 50 to 350°C, what is the output signal value, in PSI, at 198°C?
A. 5.7
B. 7.2
C. 8.9
D. 12.6
C. 8.9
- 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 number of test points. Test point readings are made:
A. Only as the pressure is slowly increased
B. Only as the pressure is slowly decreased
C. In no particular sequence
D. As the pressure is increased and the pressure is decreased
D. As the pressure is increased and the pressure is decreased
- A properly calibrated pressure transmitter connected to a 20 foot tall tank with a water level of 15 ft would indicate a pressure of approximately:
A. 19 psig
B. 10 psig
C. 180 inches of water
D. 150 inches of water
C. 180 inches of water
- The span, in inches of water, of a differential pressure transmitter used to measure the full level of a tank that is 5 foot, 6 inches high and contains a process material with a specific gravity of 0.9 should be:
A. 73.3
B. 59.4
C. 66.0
D. 5.6
B. 59.4
- Closing high and low pressure tap block valves, banking the low side to atmosphere, and connecting and applying a known calibration pressure to the high side is done to check:
A. The condition of the block valves
B. Tubing for leaks
C. Zero and span of a DP cell
D. None of the above
C. Zero and span of a DP cell
- When checking the calibration of an instrument, the first information you should record should be:
A. Original span
B. Original zero
C. Calibration data before adjustment
D. Final calibration data
C. Calibration data before adjustment
- The time constant (first order lag) in a transmission system is the time necessary (after dead time) following upset for the response curve to reach ____________ of its final value.
A. 100%
B. 63.2%
C. 50%
D. 37.8%
B. 63.2%
- Load cells and strain gauges measure the amount of material in a tank by measuring:
A. Thermal conductivity
B. Hydrostatic head
C. Ultrasonic frequency
D. Weight
D. Weight
- In the circuit below, what is the total resistance value? (Photo)
A. 9.7 ohms
B. 8.7 ohms
C. 15 ohms
D. 33 ohms
A. 9.7 ohms
- The _________ variable is a part of the process which is adjusted to close the gap between the set point and the value of the controlled variable.
A. Manipulated
B. Measured
C. Controlled
D. Disturbance
A. Manipulated
- The desired value of the process variable is called the _________.
A. Measurement signal
B. Set point
C. Controlled variable
D. Output signal
B. Set point
- An undesired change in a variable which tends to adversely affect the value of a controlled variable, is normally called a(n):
A. Process lag
B. Measurement error
C. Disturbance
D. Error signal
C. Disturbance
- In a home heating system, the room temperature is the:
A. Manipulated variable
B. Set point
C. Controlled variable
D. Disturbance variable
C. Controlled variable
- The integral action which is part of a P&ID algorithm is often called:
A. Rate
B. Reset
C. Gain
D. Insert
B. Reset
- The term “primary element” usually refers to:
A. PID control action
B. Pneumatic control valves
C. Transmitters and transducers
D. Detectors or sensors
D. Detectors or sensors
- Most pneumatic controllers:
A. Produce a 6 to 30 psig output
B. Have some type of flapper nozzle
C. Are PID controllers
D. Can accept a 4 to 20 mA input
B. Have some type of flapper nozzle
