Dmn 1/ Lvl 3 Flashcards
1
When measuring across the loop resistor (250 oluns) a voltage of 2.25 is measured.
What percent of the input range is this?
A. 22.50%
B. 25.65%
c. 31.25%
D. 56.25%
C
An electronic transmitter has a dynamic and a steady state gain. The steady state gain
A. Is almost always linear and has little effect on control of the process
B. Has little effect on overall loop stability with respect to control
C. Should be constant over the control range of the process
D.Is usually compensated for by self tuning controllers
C
With a 5 volt input signal, what number of bits is required to obtain a resolution of 0.012% using a successive approximation convertor?
A 10
B. 12 C.14 0.16
D
Computer-aided calibration systems (CAC) run a program to:
A. Reset controller set-points
B. Collect statistical data-points
C. Operate a multifunction calibration system
D. Produce calibration procedures, test data collection, calibrate data
D
During configuration and loop check of a smart pressure transmitter, the output signal is 12.01 rnA for 50.0% input (PV). Which procedure should you perform to correct this condition?
A. Sensor trim
B. Output trim
C. Valve % throw
D. Scaled Output trim
B
Which test instrument would be used if it is desired to check the calibration of a 0-800 psi pressure gauge?
A. resistor decade box with 0.1 ohm steps
B. pneumatic dead weight calibrator
C. hydraulic dead weight tester
D. capacitance tester
C
Most standard control valves are subject to what range of hysteresis (percent to total stroke)?
A. 0.5 to 1%
B. 2% to 5%
C. 8% to 10%
D. 25% to 50%
B
The output of a controller to a valve positioner with an integrally Mounted 1/Pis 15 mA . The control valve is A/ 0 and shown to be 32%
open. The current to the positioner is checked at 16 mA and the output is 6.6 psi. The technician should first check:
A. The action of the positioner.
B. The air supply to the positioner .
C. The valve operation to see if it is A/ 0 or A/ C.
D. For a leak from the I/ P to the diaphragm of the valve.
A
A deterministic network when loaded to above 70% capacity will:
A. jabber
B. beacon
C. slowdown
D. block all traffic
C
Which of the following items could cause an over 20 mA signal, regardless of input, in a thermocouple temperature sensor loop?
A. A short between signal leads
B. A reverse polarity connection
C. A low voltage supply at the transmitter
D. An open sensing element at thermocouple
D
A control valve is failing to provide positive shut-off when closed.Your first step should be:
A. Stroke it then remove for repair if needed.
B. Remove and take it to the valve shop for repair.
C. Check the positioner. It is a likely source of the problem.
D. Check the valve type, some do not provide positive shut-off
C
You are called to a facility location where a PID process appears to be oscillating. It is a single loop digital temperature
controller. After querying the operator as to his/her knowledge of the problem, a necessary first step would then be to have the:
A. PV sensor replaced immediately
B. operator perform emergency shut-down
C. valve stroked while leaving loop in automatic
D. operator place loop in manual, attempt to stabilize process
D
When using a analog to digital convertor, and it has a default output of offset binary, what must be done to convert the output signal to twos-complement?
A. Transliterate the I.SB.
B. Invert the MSB
C. Add binary 12
D. Nothing
B
Process temperature requirements are:
1) 400 deg C max,
2) Less than 1% drift/year,
3) 1.5% accuracy over span of 50 deg. C,
4) Moderate cost
You would select a: A. Thermocouple B. Thermopile C. Thermistor D. RTD
D
The statement; “Thermocouple extension wires must have the same thermo-electric properties as the thermocouple that they are used with,” is:
A. False. Extension wires must be made from either copper or brass.
B. True if the extension wires are submerged in the process fluid.
C. False. The type of extension wire makes no difference.
D. True in all installations.
D
