Domain 3 / Troubleshooting Flashcards
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 disk
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 the voltage increases
D. The emf remains the same when the 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 only at one end of the circuit
C. attaching a safety ground to the control panel
D. grounding the shield at both ends of the cable
B. grounding the shield only at one end of the circuit
A meter reading of only 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 the 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
A device used to change an analog signal to a digital signal is most often called a: A. transducer B. signal conditioner C. transmitter D. converter
D. Converter
A breadboarding area is: A. a data routing circuit B. used to design or test electronic circuits C. a code-converting circuit D. a temporary binary storage area
B. used to design or test electronic circuits
A 4-20 mA electronic transmitter has an input range of 50-330 deg. F. If the output is 13.77 mA, what is the indicated temperature in deg. F? A. 173 B. 221 C. 266 D. 302
B. 221
If the range of a 3 - 15 PSI pneumatic transmitter is 50 - 350 deg F, what is the output signal value, in PSI, at 198 deg F? A. 5.7 B. 7.2 C. 8.9 D. 12.6
C. 8.9
When the percentage of flow through a valve equals the percentage of plug movement, a valve has: A. linear flow characteristic B. equal percentage flow characteristic C. quick opening flow characteristic D. curved flow characteristic
A. linear flow characteristic
Which of the following parts of a globe valve serves the same purpose as the disk in a butterfly valve? A. seat B. plug C. packing rings D. packing flange
B. plug
The process of grinding the plug and seat of a valve is called: A. characterizing B. linearizing C. lapping D. calibrating
C. lapping
The dead band of an instrument is:
A. the band that prevents the instrument from being tampered with by unauthorized persons
B. the range of values for which the instrument gives inaccurate readings
C. the size of the instrument indicated by the divisions on the scale of the instrument
D. the range that an input signal may be changed on reversal of direction without an observable change in the output
D. the range that an input signal may be changed on reversal of direction without an observable change in the output.
A continuity check should be made prior to the hook-up of a field transmitter to the control room so that the technician:
A. can assure that the transmitter is being hooked up to the proper indicator/controller
B. cam make sure that the proper voltages ar present
C. can make sure that he continue hook-up on a particular transmitter
D. knows that he may connect another transmitter to the loop circuit.
A. can assure that the transmitter is being hook-up to the proper indicator/controller
Impulse lines are used with: A. pressure meters B. magnetic flowmeters C. positive displacement meters D. open channel meters
A. pressure meters
Which meter does not use an obstruction? A. Head meter B. Magnetic meter C. Open channel meter D. Turbine meter
B. Magnetic meter
The Coriolis effect is associated with the: A. head meter B. mass flowmeter C. positive displacement meter D. turbine meter
B. mass flowmeter
A beveled orifice should form an angle of:
A. Not less than 30 deg. to the axis of the pipe
B. not more than 30 deg. to the axis of the pipe
C. not less than 45 deg. to the axis of the pipe
D. not more than 45 deg. to the axis of the pipe
C. not less than 45 deg. to the axis of the pipe
Which orifice plate is used to eliminate damming of material at the top or bottom of the pipe? A. concentric B. round-edged C. quadrant-edged D. segmental
D. segmental