Instrument tech test review
an electrical switch is used to?
A device that makes or breaks a circuit
The set point on a controller is a specific value at which?
A specific value at which the process variable should be maintained
process flow drawings (PFD's)are used to?
Aid understanding of overall process
which of the following is a final control element in an instrument loop?
Control valve
A device at sea level is calibrated 0 to 30 Psia the gauge pressure is at 50% scale is?
.3
Five point method of calibration
0 100 50 25 75
How much pounds is water
0.027
A DCS excepts 1 to 5 volt inputs the transmitter outputs are 4 to20 MA what type of resistor should normally be installed in the analog input card?
250 ohm resistor
if 75 V potential is applied to a 25 ohm load the circuit current is?
3 Amps
Thermal couple type T
Blue + and - red
1 meter is how many inches?
39.37 inches
An instrument using high-frequency sound waves to measure fluid levels
Ultrasonic probe
When cutting steel from color-coded stock always cut from the
Unpainted end
The absence of a gas inside a container
Vacuum
The point at which a stretch piece of metal will not return to its original shape or size
Yield point
A severe shock is affected by?
amperage/amount of current in body
to create a NOR gate add an inverter to the output of?
an OR gate
The most frequent control mode is?
automatic
what are typical applications of photocells except?
automatic lighting ,position sensing, size detection
A binary system is a base _____ system?
base 2
pressure switches are actuated by?
bellows, diaphragms ,and bourdon tubes
A ration relay is a type of?
booster relay
what is a diode?
electronic device allows flow to go in one direction
viscosity is analyzed in all of the following ways?
falling ball ,capillary ,and turbine methods
an electrostatic precipitator is used to?
filters particles in a gas stream
A Valve has a linear flow characteristics when the?
flow correspond directly to the valve stem position
which turning mode will cause the controller to generate an output proportional to the PV deviation from setpoint?
gain
Cable shields should be connected to the?
grounded at signal ground reference point
increasing the carbon content in steel results in an increase in?
hardness
what communication protocol has become the most commonly used?
hart
where would an instrument fitter find the proper method to connect an instrument to a process tap?
installation details
A worker knows the tag number of an instrument and needs to identify the drawings and documents relating to the particular instrument what drawing would he need to look at?
instrument index
when drawing shows the height width and depth of a particular installation?
isometric
The most widely used form of PLC programming is?
ladder logic
The three basic types of fluid flow are?
laminar ,transitional ,turbulent
which metal property describes metal that can be shaped or formed easily?
malleability
on a field mounted controller how is the set point changed?
manually
where should we look for information concerning a hazardous chemical?
msds
electronica instrument signal leads can be influenced by the following?
noise
which metal contains little or no iron?
non-furious
asbestos gaskets are permitted as replacements in what type of installation?
none not allowed
A control mode that either opens or closes a final element is called?
on/off
A solenoid valve is normally closed meaning that the valve is ______ when energized
open
what drawing showing how something actually looks?
orthographic
in modulating control the first step is to compute an error between controlled variable and setpoint the second step is to produce an?
output signal
if a circuit provides more than one path or branch for a current to flow the loads are?
parallel connected
all of the following technologies are used in the hydrogen sulfide analyzers except?
paramagnetic sensor
The proper gasket for a flange mounted pressure transmitter on the process pipeline should be selected from the ______ index
pipe spec
what type of input signal does a valve actuator receive from a 4 to20 ma transducer?
pneumatic
pilot operated regulators are preferred where what kind of pressure control is required?
precise
gaskets are usually specified for particular ranges of?
pressure and temperature
water in an air system causes all of the following except?
pressure fluctuation
what devices are used to measure pressure?
pressure gauge
A pneumatic signal simulator can be used to calibrate?
pressure switches
what is the purpose of a lock out tag out system?
prevent unexpected energizing of equipment
when are troubleshooting flow charts most effective?
problems are identified
The term span adjustment refers to the adjustment of the?
range between the highest and lowest scale value of a instrument
what is used to reduce or maintain pressure?
regulator
when bench calibrating a temperature RTD transmitter the instrument technician should apply?
resistance because it's an RTD
when is the best time to document each loop check for commissioning?
right when completed
how should Teflon tape used as a sealant Be wrapped?
same direction as threads
where are the types of gaskets and gasket material to be used on a project listed?
section of spec's
what is the purpose of a truth table in digital logic?
show input and output possibilities
during system repair or trouble what happens to the system if the DCS goes into default?
shuts down or goes intozero output
an example of a direct measurement indicator is ?
sight glass
proving a loop is a?
simulated test run
when hardened copper is annealed it becomes?
softer
what is the primary goal for any close loop control system?
stability
every instrument used on a project should have a different?
tag number
The process parameter that is selected for control is called the ?
Control variable
Wets and lubricates machinery for threading steel and brass pipe and keeps machines running longer
Cutting oil
before working on the De-energized circuit containing a capacitor what must be done?
Discharge the capacitor
The amount of material replaced by a sensor probe as it measures level
Displacement
A shift register consists of a series of
Flip-flops
solid wedge, flexible wedge, and double disc fluid controls elements are used to classify what type of valve?
Gate valves
when using isopropyl alcohol as a cleaning agent all of the following should be avoided except?
Grease
The property of metal to resist forcible penetration or bending by another substance
Hardness
What are cutting oil's used to reduce during threading
Heat and friction
all of the following are turbidity analyzers except?
Image analyzer
Gravity of water
Is one
What causes the flow in a tank to go up or down
Liquid or fluid
Used to check low vapor pressure
Manometer
what organization issues the guidelines used for lockout procedures?
OSHA
Signal cable shields should be connected to ground at?
One point in signal path
A method of control where there is a no feedback to initiate self correcting action for the error of the desired operational conditions
Open loop
A plate containing a hole which when placed in a pipe causes a pressure drop which can be related to the flow rate
Orifice plate
The documentation required to loop check in commission are?
P&ID,Loop diagram ,and spec sheets
The standard reference material used in a resistance temperature detectors is?
Platinum
A disadvantage of direct operated regulators is?
Poor sensitivity
Can be used to reverse the signal to valve to overcome friction forces within a valve on high-pressure drop applications
Positioner
Hydraulic and pneumatic instruments are calibrated in
Psi
A temperature sensor that provides temperature readings by measuring the resistance of a metal wire
RTD
all of the following would be found on a blueprint except the?
South arrow
A control valve does all of the following?
Start stop and control
A differential pressure transmitter mounted on a non-vented vessel is used to measure the?
The level of the product in the vessel
what is density?
The ratio of a substance to the weight of a equal volume of air at a specific temperature and pressure
A temperature sensing device that uses dissimilar metal junction's to generate a voltage proportional to the differential temperature between the metal junction's
Thermocouple
The resistance force or tensile yield strength of a metal product is expressed in____ per square inch
Thousands of pounds
The property of a metal to withstand sudden shock or high impact forces without fracturing or breaking
Toughness
A TON function is?
timer on delay function
The applications of a signal passing through the hard wiring and components without leakage is and?
transmission test
in a flash point analyzer the flash point of a fluid is detected by?
unsustained flame
where should a DP flow transmitter's high-pressure side be connected to the orifice taps?
up stream
an air to open valve uses a?
uses a spring to close actuator
how is the flow measurement expressed?
velocity flow ,volume flow ,mass flow
when properly calibrated and installed the most accurate primary flow element is the?
venturi tube or coriolius meter
flow measurement is determined by fluid oscillations in which type of flow meter?
vortex meter
if water freezes at 32°F at what temperature will it freeze in degrees Celsius?
zero
Force exerted on an object by gravity
Weight
Thermocouple type J
White + and - red
Thermal couple type K
Yellow + and - red
Class 0 rubber gloves are used when working with voltage less than
1000
how many cycles in a kilo hertz?
1000
when installing packing rings how much should the cut ends be staggered?
180 degrees
The hydrostatic pressure created in a 10 foot tank with the 8 foot water level is?
2
How many gallons in 1ft of water
7.48 gallons
what part of the instrument installation drawing lists the required fittings?
Bill of materials
A Fthiotis can be used to determine the____ of steel
Carbon content
in a distribution control system actual control logic execution occurs at the?
Central processor
The corrective ingredient of an acid or base that is added to bring pH to a desirable level
Reagent
what is the purpose of an I/P in a control loop?
change current input signal to output pneumatic signal
in ladder logic relay instructions are comprised of input contacts and output ?
coils
Old packing should be replaced with new packing which is _______ compared to the old packaging
compatible
which of the following is not the type of materials used on tubing up transmitters?
copper
during a loop check what is proving a loop?
correct response between interconnecting parts of the loop
A disadvantage of an SSR is?
current leakage
A nuclear measuring device can be used to measure?
density