NCCER Flashcards
(206 cards)
1
Q
A technology bypassing conventional I/O by using direct communications between smart field devices and associated control processors is:
A
Fieldbus
2
Q
Redundant controllers in a distributed control system reside:
A
As a hot standby at the central processor
3
Q
The ultimate period method for tuning a controller was first proposed by:
A
Ziegler and Nichols
4
Q
One method of oxygen analysis focuses on the:
A
Color properties of Oxygen
5
Q
A piece of pipe has an AISI classification of A105, The major alloy is:
A
Carbon
6
Q
Atmosphere testing must be conducted before entry into a confined space to check for:
A
Oxygen Content
7
Q
Wish of the following contains information about chemicals found on a job site?
A
Material safety data sheet
8
Q
Which of the following materials is selected when resistance to corrosion or high temperatures is required?
A
stainless steels
9
Q
Which of the following is a type of gasket used in high-pressure systems?
A
metal Ring joint
10
Q
Examples of inactive cutting oil include all of the following EXCEPT;
A
Sulfurized mineral oils
11
Q
Which of the following thread sealant is MOST suitable for service temperatures of 500 to 700 degrees Fahrenheit?
A
Graphite Paste
12
Q
A system installed to provide protection of equipment from line-to-ground fault damage is called;
A
Ground-fault circuit interrupter (GFCI)
13
Q
Increasing the Carbon content in steel results in an increase in:
A
Hardness
14
Q
The beveled edge of an orfice plate faces
A
Downstream
15
Q
A bourdon tube is normally found inside a:
A
Pressure guage
16
Q
A loop sheet contains all of the following information EXCEPT:
A
The calibration and specification
17
Q
A temperature-measuring device that operates on the principle that electrical resistance changes with temperature is a
A
Resistance Thermal device (RTD)
18
Q
capillary tubing with a bulb on the end is normally used on instruments that provide
A
temperature readings
19
Q
A bourdon tube typically is used to measure
A
Pressure
20
Q
what is the relationship of absolute pressure and gauge pressure
A
psia= psig + atmospheric pressure
21
Q
process flow drawings(PFDs) are used to:
A
Aid in understanding the overall process
22
Q
A material safety Data Sheet (MSDS) has all of the following sections EXCEPT:
A
Disposal Contractors
23
Q
Which of the following tools should be used to remove old packing from the packing gland?
A
Packing extractor
24
Q
Approximately what is the pressure, is psi, at the bottom of a 20-foot high tank filled with a fluid that has a specific gravity of 1.5?
A
13.0 psi
25
the drawing that shows how similar devices are to be installed and connected is an instrument:
Detail drawing
26
In a bubbler system measuring level from the bottom to the top of the vessel the dip tube is installed in a vessel with its open end:
Just above the bottom of the vessel
27
which wiring diagram does not show discrete conductors from end to end, but in a bundle?
Raceway diagram
28
when one controller is used to control two final elements it is known as:
Split range
29
In modulating control the first steps is the compute the error between controled variable and setpoint. The second step is to produce a(n):
Output signal
30
when used as a film between two surfaces, lubricants will reduce all of the following EXCEPT
Leakage
31
The letters "EL" on a blueprint stand for
Electronic line
32
Significant numbers are:
In front of the decimal
33
A proportional band of 100% is the equivalent to a gain of
1
34
what type of instrument loop uses feedback to correct change
Closed-loop
35
The component in an Instrument system that detects process change is the:
Primary element
36
A pressure transmitter connected across an orfice plate measures:
The differential pressure across the plate
37
What is the PRIMARY purpose for filing a pressure gauge case with glycerin?
Pulsation dampening
38
What part of a loop or an instrument first senses the value of a process variable, such as the level of liquid in a tank or the temperature of product?
Primary element
39
Where are the high and low sides connected when a differential pressure instrument is used to measure the level of a vessel with an operation/
The high side is connected to the bottom of the vessel, and the low side is vented to the atmosphere.
40
A control mode that either opens or closes a final elements is called
On/off
41
In order to take direct control over a process, the controller should be places in
Manual control
42
The operation modes of a loop controller are
Manual,Automatic, and cascade
43
Proportional controller is defined as a control
Mode in which the contoller produces a corrective signal that is proportional to the controlled variable's percentage of deviation from the setpoint
44
where does the diaphram of springless, pneumatic actuator control valve use air pressure?
On both sides
45
An acutator on a regulating valve converts thermal,electrical, or fluid energy into electro-pneumatic energy
Mechanical energy
46
What type of control valve actutor is used MOST often?
pneumatic
47
A time delay is energized and 10 seconds pass before the contact in the relay are actuated. This is an example of
On-delay
48
A drawing that illustrates the physical components of a system, including its piping, valves, and instrumentation, is called:
P&ID
49
Which of the following is another name for synchronous time switch?
Dashpot Timer
50
Which of the following is controlled directly by an electrical relay?
Contacts
51
Pilot-operated regulators are prefered where what kind of pressure control is required?
precise
52
When a pressure switch is used as a low limit, deadband refers to the:
Distance from zero at which the switch returns to shelf state
53
An air dryer using a solid desiccant that does not liquefy is known as:
Absorptive
54
Which of the following INCREASES the inductance of a circuit?
Increasing number of turns in a coil
55
the capacity of a regulator when it has failed fully open is usually
greater than the regulating capacity
56
Why are air dryers an essential part of a pneumatic system used in instrumentation?
To eliminate moisture
57
Once ambient air is compressed then discharged from a compressor, its temperature is elevated and its moisture content is
low
58
In MOST cases, the cable shield will be attached
At one end
59
If all AND gates inputs are true, the output will be:
True
60
What is the digital element used to deny a burner ignition sequence if the fual gas pressure is abnormal, there is no air flow,or there is no pilot flame?
AND gate
61
To create a Nor gate, add inverter to the output of:
An AND gate
62
What would be the gain of a system with an input change of 20% and an output change of 10%
0.5
63
Which of the following describes SPAN?
The difference between 3 and 1
64
If the process is stable but controlling away from setpoint, what is needed to CORRECT the problem?
Decrease the derivitive
65
When bench calibrating a pressure transmitter, the instrument technician should apply
Air pressure in psi
66
Which tuning mode will cause the controller to generate an output proportional to the PV deviation from setpoint?
Reset
67
A pneumatic signal simulator can be used to calibrate
Pressure switches
68
When an electronic D/P cell is calibrated, the simulated inout pressure should be connected to the transmitter's
High Side
69
The term "Span adjustment" refers to the adjustment of the
Range between the highest and lowest scale value of an instrument
70
When bench calibrating a temperature RTD transmitter, the instrument technician should apply
Resistance
71
As a general rule, before the smart communicator can be utilized, loop resistance MUST equal a MINIMUM of
250 ohms
72
Setting the relationship between the input signal and the response, or output, of a device is known as:
Calibration
73
Performing visual inspection to verify mechanical installation of loop components includes:
All components including process connection, primary, control elements, and wiring
74
When calibrating a flowmeter that uses a turbine sensing element, the instrument technician might use
A pulse source and milliamp
75
A bubbler is used as feedback in what type of system?
Pneumatic
76
Which turning mode will drive the PV to setpoint, thus eliminating offset?
Proportional
77
Ideally, functional verification of a loop is done through:
Process Simulation
78
The standard reference material used is resistance temperature detectors is
Platinum
79
The most widely used form of PLC programming is
Ladder logic
80
What communication protocol has become the most commonly used?
Hart (tr)
81
With a smaller intergral time, the output of a PID controller will be
Larger
82
In PLCs, how many possible stated do discrete inputs have?
Two
83
The term Topology is used with digital control systems to describe:
Configuration of data registers and processors
84
DCS stands for
Distributed Control System
85
In a test of the accuracy of a pneumatic comparator with a pressure guage, pressure readings of the test guage being tested are compared at a number of test points. Test points readings are made:
As the pressure is both increased and decreased
86
when a sensor is inserted in a thermowell, which of the following could safely improve response to temperature changes?
Antifreeze
87
What type of transducer converts the variable being measured into a voltage generated by a crystal when it is mechanically stressed?
Piezoelectric ( used in DP cells)
88
Changing the proportional band of a pneumatic controller changes:
The gain
89
A power supply component that reduces the ripple in the waveform is a:
Filter
90
What provides a warning when low and/or high limits of optimum range are being approached?
Absolute alarm points
91
A device that converts alternating current to direct current is called a:
Rectifier
92
The oil within the variable capacitor of a capacitance-type differential pressure transmitter is separated from the process by:
A sensing diaphragm
93
When a dip pipe (bubble) system is used for tank level measurement, the dip pipe is connected to:
The purge gas flow meter
94
What type of control has the most offset:
On-Off
95
Hydrostatic head level can not be measured with a:
resistance Probe
96
What is not necessary when zeroing or calibrating a magnetic flowmeter?
Calibration factor for the flow tube assembly
97
Closing high and low pressure tap block valves, venting low side to atmosphere, and connecting and applying a known calibration pressure to the high side is done to check:
Zero and span of a DP cell
98
Noise can affect instrument performance directly when it:
Is created by a ground loop
99
What primary element does not produce a differential pressure to measure flow:
Thermistor
100
What occurs if the temperature of the thermocouple measuring junction is lower than the reference junction?
The output voltage polarity is reversed
101
What temperature sensor produces an output resistance directly related to the temperature of the device?
RTD
102
Limit switch cams are usually found in:
Electric motor actuators
103
What is not a characteristic of positioners?
Allow for biasing the valve
104
Which of the following types of actuators responds to a pneumatic signal?
Diaphragm
105
When the percentage of flow through a valve equals the percentage of plug movement, a valve has:
Linear flow characteristic
106
To ensure the accuracy of a pneumatic controller throughout its range, you must precisely adjust:
Input
107
If a controller does not have full output when the manual adjustment is rotated to move the output pressure to full scale, the LEAST likely source of the problem would be:
proportional band setting
108
If nozzle back pressure does not decrease when it should, the most likely cause is :
Nozzle clogged with dirt
109
Input to the ___ bellows flows through an adjustable restriction.
Reset
110
Changing the proportional band of a controller changes:
The alignment of the controller
111
A low resistance reading from an underground signal lead connected to ground indicates a problem of:
A lead having an unwanted connection to ground
112
What can provide input/output isolation?
Optical coupling
113
The term used to describe multiple lines sending eight bits of data at a time is:
Serial Transmission
114
An oscilloscope waveform spans 5.5 vertical divisions. the vertical gain control is set at 2 volts/division/ the peak-to-peak voltage of the signal on the oscilloscope is:
11 volts
115
A breadbording area is:
Used to design or test electronic circuits
116
The digital test device that captures and displays a sequence of instructions from the program of a microcomputer is a:
Logic probe
117
A diamond on an instrumentation diagram encloses information about:
The power source
118
The density of a liquid affects the displacer's:
bouyancy
119
What mode MUST the controller be in before any changes are made to the process variable?
manual
120
Bills of materials are found in:
general arrangement drawings
121
When bench calibrating a temperature RTD transmitter, the instrument technician should apply:
resistance
122
Before working on a de-energized circuit containing a capacitor, what must be done?
Discharge the capacitor
123
The MINIMUM value of the measured process range is considered to be:
3psi and 4mA
124
A solenoid valve is ofen used to:
Direct airflow that opens or closes an air-operated valve
125
Viscosity is not analyzed in:
the viscositron method
126
The process parameter that is selected for control is called the:
Controlled variable
127
Optimal gain is the MAXIMUM allowable value of gain in which the system is:
Stable
128
Carbon dioxide is produced commercially:
as a byproduct of manufacturing
129
The MOST reliable relay is an:
SSR
130
In modulating control, the first step is to compute the error between controlled variable and setpoint. the second step is to produce an:
Output signal
131
A dashpot timer relay:
is a type of pneumatic relay
132
A photosensor is a:
Silicone-controlled rectifier
133
Signal cable shields should be connected to ground at:
1 point in the signal path
134
What best determines the required torque for bolt tensioning?
Grade of bolt
135
Old packing should be replaces with new packing which is:
In kind
136
Atmosphere testing must be conducted before entry into a confined space to check for:
Oxygen Content
137
A DCS accepts 1 to 5-volt inputs. The transmitter outputs are 4-20 mA. What type of resistor should normally be installed in the analog input card?
250.0 ohms
138
Density is analyzed using all the following methods EXCEPT:
peptide
139
In a flash point analyzer the flash point of a fluid is detected by:
an unsustained flame
140
When selecting a regulator, chose the:
Overpressure protection that protects the regulator
141
A decreasing output with increasing input describes:
Reverse action
142
The basic element of the shift register is the:
Flip-flop circuit
143
The program that is permanently enterened into a PLC processor is called:
Firmware
144
Needle valves are used for
Low flow, high pressure drop, precision flow control
145
In a properly grounded system:
Excess voltage and current are rapidly directed to the earth
146
Pressure is expressed mathematically as:
Decreases when controller signal increases
147
Single-point grounding of signal cable shields:
Drains induced voltage from shields
148
A valve has linear-flow characteristics when the:
differential pressure corresponds directly to the valve stem position
149
A timely delay is energized and 10 seconds pass before the contacts in the relay are actuated. This is an example of:
ON-Delay
150
Which of the following is used to calibrate a DP transmitter?
Wally Box
151
Troubleshooting flow charts are most effective when:
Problems are identified
152
What instrument drawing shows an actual representation of a process operating sequence?
P&ID
153
The binary System is a base:
2 system
154
A common unit for volume of a gas is:
SCFM
155
Pressure switches are actuated by:
bellows, diaphragms, or bourdon tubes
156
The word "piezoelectric" refers to a certain class of crystals that produce an electric signal when they are mechanically:
Deformed
157
An orfice plate causes a pressure drop which can be measured to calculate:
Flow
158
Significant digits:
describe accuracy limits of a measurement or calculations
159
"proving" a loop involves:
Verifying desired interaction of loop components through simulation
160
The types of gaskets and gasket materils to be used on a project are listed in:
a section of the specifications
161
1 meter is:
39.3 inches
162
If the proportional band of a controller is adjusted to the MINIMUM possible value, the controller action is likely to be:
Excellent
163
The operation modes of a loop controller are:
Manual, automatic, and cascade
164
The span of an instrument with 24-36 psig is:
12psig
165
What valves aren't used to regulate flow:
Gate
166
What tool should be used to remove old packing from the packing gland>
Packing extractor
167
Device used to check the integrity of tubing is the:
Wallace and Tieman calibrator
168
A controller receives an input signal from a:
Measuring element
169
On a field mounted controller, the set point is changed:
By the control room operator
170
What is a thermowell?
Protective device to house a thermocouple
171
What is the major cause of death from electrical shockl/
Heart fibrilation
172
The hydrostatic pressure created in a 10 foot tank with 8 feet water level is:
8psi
173
An example of a direct measurement indicator is a:
Pressure guage
174
To create a NOR gate, add an inverter to the output of:
an OR gate
175
Which of the following must be determined before selecting a pressure-reducing regulator?
Capacity required
176
Gaskets are usually specified for particular ranges of:
Temperature and pressure
177
What is the formula for pressure
P=F/A
178
A chromatograph is used to:
determine the chemical composition of a liquid or gas
179
What adjustments on a pressure transmitter sets the minimum range value
Zero
180
Proving a loop is a:
Simulated test run
181
When tuning a controller, increasing gain:
increases sensitivity
182
Which of the following materials is selected when resistance to corrosion or high temperastures is required?
Nickel Alloy
183
Loop testing involves simulation of the:
process variable
184
What describes span
The difference between 3 and 15
185
When a pressure switch is used as a low limit, deadband refers to the:
Distance from zero at which the switch returns to shelf state
186
A bubble isused as feedback in what type of system?
Pneumatic
187
A thermocouple is:
A temperature measuring device that produces a voltage as the temperature changes
188
A common operational feature of regulators is:
an input to provide the desired output
189
A flow meter BEST suited for suspended solids is a:
Target flow meter
190
DCS stands for
Digital communication system
191
Where would an instrument fitter find a P&ID number for a particular instrument?
in an instrument index
192
The hardness of a metal is reflected in its ability to resist:
Denting
193
What are not Instrument drawings?
pilot diagrams
194
What is not true about direct process recorders?
They aren't used in a control center
195
DCS control functions take place in the:
Central computer
196
How is an annunciator used in a control room?
To signal alarms from a field location to the control room
197
A confined space is identified as:
having limited entry and exit
198
The setpoint on a controller is a specific value at which:
a process variable is to be maintained
199
The proper gasket flange-mounted pressure transmitter on a process pipeline should be selected from the:
Service index in the pipe specification book
200
When is the BEST time to document each loop chack for commissioning?
At the time each test is completed
201
In ladder logic, relay instructions are compromised of input contacts and output:
Contacts
202
Teflon tape used as a sealant should be wrapped:
In the same direction as the threads
203
What drawing shows the height, width, and depth of a particular installation?
Isometric drawing
204
A DCS work station may Not do:
Configure Logic
205
Which tuning mode will cause the controller to generate an output proportional to the PV deviation from setpoint?
Gain
206
An electrostatic precipitator is used to:
Remove particulates in a gas stream
