Domain 2 Flashcards
- A Coriolis flowmeter is ranged 0 to 100 lbs/hr (0-45.36 kg/hr) and has an output of 14 mA. What is the process variable reading?
A. 6.25 lbs/hr (2.83 kg/hr)
B. 62.5 lbs/hr (28.3 kg/hr)
C. 8.75 lbs/hr (3.97 kg/hr)
D. 87.5 lbs/hr (39.7 kg/hr)
B. 62.5 lbs/hr (28.3 kg/hr)
- A megohmmeter is used to measure which of the following?
A. Conductor resistance
B. Conductor voltage
C. Insulation voltage
D. Insulation resistance
D. Insulation resistance
- When performing a calibration check, you find it a 4-20 mA output linear transmitter has a reading of 8.05 mA at 25% input, what is the full-scale error?
A. .313%
B. 31.2%
C. .05%
D. 5%
A. .313%
- A diamond on instrumentation diagram encloses information about:
A. Calibration
B. The set point
C. Controller action
D. The power source
B. The set point
- Central connection points for signal lines are called:
A. Instrument ports
B. Junction boxes
C. Input/output junctions
D. Field ports
B. Junction boxes
- In the following diagram, what is the proper range to set up the transmitter if the low side is a wet leg? (see photo)
A. LRV = -280 InH2O (711.2 cmH2O), URV = 0 InH2O (0 cmH2O)
B. LRV = -324 InH2O (823 cmH2O), URV = -12 InH2O (30.5 cmH2O)
C. LRV = 0 InH2O (0 cmH2O), URV = 280 InH2O (711.2 cmH2O)
D. LRV = 0 InH2O (711.2 cmH2O), URV = 336 InH2O (853.4 cmH2O)
B. LRV = -324 InH2O (823 cmH2O), URV = -12 InH2O (30.5 cmH2O)
- In an electronic loop diagram, junction box connections are represented by:
A. Circles
B. Diamonds
C. Ellipses
D. Squares
D. Squares
- Some flange mounted devices cannot be valved out of process piping. In such cases isolation from dangerous process materials and pressures is obtained by a metal disc known as a:
A. Blank
B. Plate
C. Stop
D. Blind
D. Blind
- The thermostat for a central air conditioning system is set at 68°F. This value is an example of the:
A. Manipulated variable
B. Deviation
C. Set point
D. Controlled variable
C. Set point
- To convert the output from a thermocouple to a standard 4-20 mA instrument signal, a(n) ___________ with cold junction compensation would be used.
A. I/P transducer
B. P/I transducer
C. D/A converter
D. mV/I transducer
D. mV/I transducer
- Iron constantan thermocouples are designated by the letter:
A. T
B. J
C. B
D. S
B. J
- To change the 4 to 20 mA analog signal from a transmitter to the signal required by a digital controller, a(n) ____________ must be part of the instrument signal loop.
A. I/P transducer
B. Signal conditioner
C. D/P transmitter
D. A/D converter
D. A/D converter
- A device that changes a voltage signal to a current signal is normally referred to as a(n):
A. P/I transducer
B. E/I transducer
C. D/P transmitter
D. V/C converter
B. E/I transducer
- A pneumatic control valve, without a positioner, is the final control element in an instrument loop. The transmitter and controller are both electronic. In order for this control system to operate, a(n) _________ must be installed in the instrument signal line between the controller and the control valve.
A. I/P transducer
B. mV/I transducer
C. D/A converter
D. P/I transducer
A. I/P transducer
- The transmission signals considered standard for most instrument systems are:
A. 4 to 20 PSI and 3 to 15 mA
B. 0 to 24 V and 0 to 20 PSI
C. 3 to15 PSI AND 4 to 20 mA
D. 0 to 20 mA and 0 to 15 psi
C. 3 to 15 psi and 4 to 20 mA
- In most process control systems the final control element is a:
A. Transmitter
B. Sensor
C. Controller
D. Valve
D. Valve
- A control valve with a direct acting actuator with springs and is air to close will:
A. Fail closed
B. Maintain position
C. Fail open
D. Fail indeterminate
C. Fail open
- A pneumatic valve actuator that operates over an instrument signal range of 9 to 15 psi is referred to as:
A. Split range
B. Failsafe
C. Air to close
D. Full range
A. Split range
- RTD is short for:
A. Reactive tuning deviation
B. Resistance temperature detector
C. Resistance tone dampening
D. Resonant temperature device
B. Resistance temperature detector
- What is the device that changes a voltage signal to a current signal?
A. P/I transducer
B. E/I transducer
C. D/P transmitter
D. V/C converter
B. E/I transducer
- While increasing the pressure during a performance test, if you overshoot the specified test point by small margin, you should:
A. Take the reading at the pressure you have reached
B. Reduce pressure gradually to the test point value
C. Reduce pressure to zero and start again
D. Reduce pressure to below the test point increase it again until the test point is reached
D. Reduce pressure to below the test point and increase it again until the test point is reached
- In this “bubbler” level control application, FI-1:
A. Sets LIC-set point
B. Controls purge gas flow
C. Controls gas pressure
D. Indicates purge gas flow
D. Indicates purge gas flow
- Which of the following types of actuators responds to a pneumatic signal?
A. Solenoid
B. Motor
C. Diaphragm
D. Electromagnetic valve
C. Diaphragm
- Changing the point of origin for input data, and the output signal destination is easy with the distributed control system because many changes can be implemented by:
A. Relocating wire jumpers in a junction box
B. Changing the pneumatic tubing connections
C. Reassigning inputs/outputs by changing loop configuration
D. Installing new transmitters and final control elements
C. Reassigning inputs/outputs by changing loop configuration
- What is a thermowell?
A. Protective tube
B. Type of manometer
C. Expandable bulb
D. Reservoir
A. Protective tube
- The body of a valve may contain packing material that prevents leakage:
A. Along the valve stem
B. Between the seat and the disc
C. Between the bonnet and the body
D. Between the inlet and outlet ports of the valve
A. Along the valve stem
- Which type of flowmeter does a rotor mounted axially within a pipe between a set of bearings describe?
A. Magnetic
B. Turbine
C. Water meter
D. Venturi tube
B. Turbine
- Which type of flowmeter measures flow by measuring volume directly?
A. Coriolis
B. Magnetic
C. Positive displacement
D. Differential pressure
C. Positive displacement
- What occurs if the temperature of the thermocouple measuring junction is lower than the reference junction?
A. There is no EMF output
B. The output voltage polarity is reversed
C. The polarity stays the same but voltage increases
D. The EMF remains the same when temperature changes
B. The output voltage polarity is reversed
- A ground loop on shielded cable can be avoided by:
A. Attaching a safety ground to the instrument casing
B. Grounding the shield at only one end of the circuit
C. Attaching a safety ground to the control panel
D. Grounding the shield of both ends of the cable
B. Grounding the shield at only one end of the circuit
- A meter reading of 1 ohm between an ungrounded signal lead and the earth ground indicates a problem of:
A. A lead having an unwanted connection to ground
B. An open circuit from the lead to ground
C. An open circuit from the lead to the casing
D. None of the above
A. A lead having an unwanted connection to ground
- What kind of wires in a process control loop would most likely be shielded cables?
A. Power wires
B. Ground wires
C. Signal wires
D. Control wires
C. Signal wires