問題一覧
1
Pressure is expressed mathematically as:
P= F/A
2
The most reliable relay is a/an:
SSR
3
How is an annunciator used in a control room
To signal alarms from a field location to the control room
4
A transmitter has a range 0-304.7" wc. What is the range in PSI?
0-11 psi
5
When bench calibrating a temperature RTD transmitter, the instrument technician should apply:
Resistance
6
A pressure instrument, measuring level in an 80-foot water storage tank on the structure above the instrument, sees a static head of about 120 feet when the tank is at zero level. The upper range the instrument must measure is no more than:
100 psi
7
Which of the following describes span?
The difference between 3 and 15
8
Signal cable shields should be connected to ground at:
1 point in the signal path
9
How many cycles is a kilohertz
1000
10
When tuning a controller, increasing gain:
Increases precision
11
in modulating control, the first step is to compute the error between controlled variable and setpoint. The second step is to produce a(n):
output signal
12
Cutting oil are classified as:
Active & inactive
13
Viscosity is analyzed in all the following ways except:
The viscositron method
14
On what principle do mass flow meters operate?
Coriolis
15
When an electronic D/P cells is calibrated, the simulated input pressure should be connect to the transmitter's
High side
16
Optimal gain is the maximum allowable value of gain in which the system is:
Stable
17
Multiple instruments within a loop share a common:
Loop number
18
1 PSI=
27.7 inches of water in of H2O
19
A time relay is energized and 10 seconds pass before the contacts in the relay are actuated. This is an example of:
On-delay
20
The instrument signal the line symbol (- - - - - ), a broken line with no marks drawn it, represents
An electric signal
21
The pneumatic output of a 3-15 psi instrument is 50%. The actual output in pressure is:
9 psi
22
Increasing the carbon content in steel results in an increase in:
Hardness
23
When using a DP transmitter for flow measurement, what is the most commonly used Primary element?
Orifice plate
24
A solenoid valve is often used to:
Direct air flow that opens or closes an air-operated valve
25
The binary system is a base
2 system
26
The ultimate period method for tuning a controller was first proposed by:
Ziegler and Nichols
27
All of the following valves are used to regulate flow, except:
Gate
28
The process parameter that is selected for control is called:
Controlled variable
29
If all AND gate inputs are true, the output will be:
True
30
Which of the following thread sealants is most suitable for service temperature to 700 degrees F
Graphite paste
31
The minimum value of the measured process range is considered to be:
3 psi and 4 ma
32
Proving a loop is a :
Simulated test run
33
The span of an instrument with 24-36 psig input is:
12 psi
34
The standard reference material used in resistance temperature detectors is
Platinum
35
What kind of resistance should be present when checking for grounds
Low or none
36
Single-point grounding of signal cable shields:
Drains induced voltage from shields
37
Gaskets are usually specified for particular ranges of:
Temperature and pressure
38
A bourbon tube is normally found inside :
Pressure gauge
39
A PLC is controlled by:
Microprocessors
40
Which of the following is a type of gasket used in high- pressure systems?
Metal ring joint
41
Which of the following is used to calibrate a DP transmitter?
Wally box
42
Which of the following materials is selected when resistance to corrosion or high temperatures is required ?
non ferrous alloy
43
In properly grounded system:
Excess voltage and current are rapidly directed to the earth
44
Troubleshooting flow charts are most effective when
Problems are identified
45
DCS stands for:
Distributed Control System
46
Carbon dioxide is produced commercially
As a byproduct of manufacturing
47
Bills of material are found in:
General arrangement drawings
48
Density is analyzed using all the following methods except:
Air bubbler
49
At high altitudes, the atmospheric pressure is
Lower than the atmospheric pressure at lower altitudes
50
All of the following are volumetric flow rates except:
SCGF
51
1 meter is:
39.3 inches
52
Which test equipment below is most suitable for calibrating a temperature transmitter with a thermocouple-sensing element?
Milivolt simulator
53
Pressure switches are actuated by:
Bellows, diaphragms, or bourbon tubes
54
Significant digits:
Describe accuracy limits of measurement or calculation
55
All of the following are typical applications of photocell except:
Size detection
56
What is a thermowell?
Protective device to house a thermocouple
57
A DCS accepts 1-5 volt input. The transmitter outputs are 4-20 mA. What type of resistor should normally be installed in the analog input card?
250.0 ohms
58
what mode must the controller be in before any changes are made to the process variable
Manual
59
What is the major cause of death from electrical shock
Heart fibrillation
60
Which of the following adjustments on a pressure transmitter sets the minimum range value?
Zero
61
The hardness of a metal is reflected in its ability to resist:
Denting
62
A Chromatograph is used to:
Determine the chemical composition ofa liquid or gas
63
A controller receives an input signal from a :
Measuring element
64
Pressure is expressed mathematically as:
Decreases when controlled signal increases
65
Atmosphere testing must be conducted before entry into a confined space to check for:
Oxygen content
66
A flow meter best suited for suspended solids is a :
Target flow meter
67
The greatest inaccuracy of a differential pressure level detector is caused by a change in the
Density of the liquid being measured
68
In a normal DP cell calibration, the low- pressure side is:
Vented to the atmosphere
69
The hydrostatic pressure created in a 10 foot tank with 8 feet water level is:
8 psi
70
The program that is permanently entered into PLC processor is called:
Firmware
71
A valve has a linear-flow characteristics when the:
Differential pressure corresponds directly to the valve stem position
72
All of the following are loop tuning parameters except
P&ID
73
A dashpot timer relay:
Is a type of pneumatic relay
74
What best determines the required torque for bolt tensioning?
Grade of bolt
75
The device that is used to check the integrity of tubing is the:
Wallace and tieman calibrator
76
The density of liquid the displacer's:
Buoyancy
77
A Photosensor is a :
Silicone-controlled rectifier
78
A decreasing output with increasing input describes:
Reverse action
79
Before working on a de-energized circuit containing a capacitor, what must be done?
Discharge the capacitor
80
Most pneumatic receivers operate in the range of:
3-15 psi
81
A common unit for volume of gas is:
SCFM
82
A gauge pressure of 195 psi is roughly what in psia
210