-
Gaskets and o-rings are two kinds of _______ seals.
Mechanical
-
O-rings require a(n)_________ to create a seal.
Groove
-
__________ compensate for temperature fluctuations in a control loop.
Expansion loops
-
__________ achieve a tight seal by forcing the flared edge of the tubing up against the tapered end of the fitting body.
flared fittings
-
______ tubing is corrosion-resistant and suitable for high-temperature, high-pressure applications.
stainless steel
-
Leak detector fluid is essential when trying to locate ____ leaks in instrument connections.
air
-
Metals that are to be soldered must be thoroughly cleaned _______ flux is applied.
before
-
Flux and discoloration may be removed from the fitting after a joint has been made using____.
-
The preferred cutting tools for stainless steel tubing are ___
tube cutters
-
_____ are food tools for removing dirt, oil and other residue from fittings and tubing before solder is applied.
- emery cloths
- lint-free cloths
-
The materials of which mechanical seals are made must be ____ with the process materials of the applications in which they are used.
Compatible
-
Bends require ______ tubing than square corners.
less
-
The wall thickness of tubing is determined by its ______.
inside and outside diameters
-
________ tubing may be found as a single tube or as a bundle of single tubes within a protective sheath.
plastic
-
Flux residue can sause stainless steel tubing to ______.
corrode
-
Applications in which pneumatic signals must be carried between instruments commonly use ___ and___
- plastic tubing
- stainless steel tubing
-
Every electrical connection should be tested for ___ after any installation or repair work is done.
resistance
-
it is essential to _________ before beginning any work on a circuit in the field.
verify the circuit de-energized
-
With coaxial cable connectors, the cable shield is usually inserted through a hole in the _______.
grounding tab
-
Check _________ terminal connections from the point at which the lost signal symptom appears.
sequential
-
The voltage rating of a wire is determined by the ____ of the conductor.
insulation
-
According to ohm's law, if voltage remains constant and resistance decreases, current will _____.
Increase
-
a poor solder joint will be ___
-
metal bubbling up form the access hole in a coaxial cable connector indicates that the joint is ____.
solid
-
____ is used to protect instrument signals passing through lines of flux from high-voltage equipment form being distorted or lost.
shielded cable
-
Grounding a shielded cable at ____ can create a ground loop.
two points
-
________ tests should be done on every electrical connection after any installation or repair work is done.
resistance
-
when verifying that a circuit is de-energized, it is important to test the operation of the multimeter ____ testing the circuit.
before and after
-
when installing a coaxial calbe connector, the _____ is usually inserted through a hole in the grounding tab
shield
-
Check sequential terminal connections from the point at which the lost signal symptom appears for ____
- loose connections
- frayed wires
- broken conductors
-
_______ is the difference between the actual value of the measured variable and the value of the variable indicated by the instrumentation.
instrument error
-
factors that should always be considered when analyzing an instrument's accuracy rating are _____ and ________.
- rangeability
- mounting position
-
Errors that can be observed on a calibration curve or input/output graph include ______, ___,___, and ____.
- zero shift
- hysteresis
- span error
- non-linearity
-
characteristics that affect an instrument's accuracy in terms of the manufacutrer's accuracy rating include dead band, linearity, ______ and ______.
-
an instrument is ___ if it is capable of consistently providing repeatable values for a given input.
precise
-
position errors may be caused by _____.
- calibrating in position different from installation position
- mechanical deformation of instrument
-
in order to permit the observation of linearity apart from the phenomena of hysteresis and dead band, it is necessary to plot an ___ curve.
average curve
-
______ is the closeness of agreement among several consecutive measurements of an instrument's output values.
repeatability
-
errors in interpretation may be caused by __.
parallax
-
instrument errors that can usually be corrected during calibration include _______.
None of the above. answers to choose from are, non-linearity/hysteresis/dead band.
-
errors in __________ may be caused by misreading the value of scale subdivisions or incorrectly estimating readings in which pointer s located between divisions or subdivisions.
parallax
-
on an input/output graph, a zero shift line ____.
all of the above, may be above the ideal line/may be below the ideal line/will not intersect the ideal line.
-
linearity is expressed as a
percent of output
-
with _____, the response of the sensing element does not catch up to the input signal until the upper or lower ranges of the instrument are approached.
hysteresis
-
the smallest change in a measured variable to which an instrument will respond is a characteristic known as
sensitivity
-
on an input/output graph, ____ is represented as a straight line that is at a different angle than the ideal line.
span error
-
with _______, all of the output readings are either consistently high or consistently low throughout the entire range.
zero shift
-
____ is the ratio of the maximum to minimum values of a measured variable that an instrument can measure within stated accuracy to the minimum value of the measured variable that it can measure with stated accuracy.
turndown
-
an instrument's repeatablility is expressed as
percentage of output span
-
_______ is the ratio of the instrument's maximum full scale range to its minimum full scale range.
rangeability
-
which of the following instrument errors can generally be adjusted.
-
which of these occurrences normally requires that an instrument should be re-calibrated?
extended shutdown
-
what is the signal range of an analog electronic pressure transmitter?
4-20 mA
-
which of the following is the first step in a good calibration procedure?
determination of signal range
-
the proper formula used to determine the accuracy of a temperature tranmitter is:
accuracy = deviation/signal span * 100
-
gain is a function of
input/output relationship
-
in looking for indications of hysteresis, it is essential to
take upscale and downscale readings
-
the accurate measurement and comparison of an instrument's inputs and outputs to a known standard is a definition of
calibration
-
the most accurate standards are those with the _____ tolerances.
smallest
-
________ standards use physical properties of matter and physical laws to provide a standard for comparison.
primary
-
calibration certification facilities use standards from _______ to calibrate their standards.
NIST
-
manometers can indicate pressure in
- inches of water
- psi
- inches of mercury
-
in order to obtain an measurement from a u-tube manometer, it is necessary to read
both legs
-
to ensure accurate calibrations, gloves should be worn when handling the ____ used with dead weight testers
weights
-
when selecting piston/cylinder assemblies, it is good practice to choose the ____ available tester range that includes the pressure range of the instrument to be calibrated.
lowest
-
the operating fluid in pneumatic testers is a
gas
-
in a pneumatic dead weight tester, the pressure balance point is achieved by forces acting on a ______ assembly.
ball and nozzle
-
the least accurate standard are those with the _____ tolerances.
widest
-
_______ standards are extremely precise instruments used for the calibration of plant instruments and systems.
secondary
-
calibration certification facilities provide standards for _________ to use to calibrate their standards.
industrial plants
-
in a u-tube manometer, the reference level is the term used to describe the level apparent when pressure is ______.
not being applied.
-
the _______ is the curve of the fill fluid level.
meniscus
-
a (n) __________ manometer is designed to provide greater accuracy from measuring small pressure changes.
inclined
-
____ are sets consisting of precision parts that are not interchangeable with components in other sets.
cylinders and weight systems
-
flushing the connection before connecting the test instrument to be calibrated to a hydraulic dead weight testers instrument connection port ensures that there are no _________ in the system.
air bubbles
-
the operating fluid in hydraulic testers is a ____
-
in a hydraulic dead weight tester, the pressure balance point is achieved by forces acting on a ____ assembly
piston and cylinder
-
what features may be found on test gauges that differ from those found on general-purpose pressure gauges?
- mirrored scales
- multiple scales
-
_________ is an optical illusion created by the distance between the gauge face and the pointer, or indicator, and the angle at which the reading is viewed
parallax
-
the eyes of the viewer reading a gauge should be at a ____ angle to the scale in order to ensure accurate readings.
-
after a test gauge has been subjected to shock, it can be returned to service only after it has been
calibrated
-
in addition to functioning as primary calibration standards, deadweight testers can also be used as ______ for high pressure instrument calibrations.
input pressure sources
-
analog-display calibrators allow ______ comparison of an instruments input and output signals under test conditions.
direct
-
because most pneumatic calibrators are _________, they can be used for field checks and calibration of instruments in their normal operating locations.
portable
-
owing to the hazardous or toxic process fluids to which they may be exposed, all instruments should be _____ and __ before being calibrated.
-
during a calibration, the pressure sensor must be _________ after each pressure value has been applied.
vented
-
while setting up the unit for a calibration, the regulators on a calibrator should be checked to determine that they are at their ____ setting.
lowest
-
mirrored scales and multiple scales are more likely to be found on ___ gauges
test
-
parallax is a(n) _______ created by the distance between the gauge face and the pointer, or indicator, and the angle at which the reading is viewed.
optical illusion.
-
the eyes of the viewer reading the gauge should be at a right angle to the _____ in order to ensure accurate readings.
display
-
after a test gauge has been subjected to shock, it cannot be returned to service until it has been ____
calibrated
-
deadweight testers can be used as _____ for high pressure instrument calibrations, in addition to functioning as primary calibration standards.
input pressure sources
-
digital display calibrators allow ______ comparison of an instrument's input and output signals under test conditions.
direct
-
because most digital-display pneumatic calibrators are ____, they can be used for field checks and calibration of instruments in their normal operating locations.
portable
-
all instruments should be ____ and ____ before being calibrated, due to the hazardous or toxic process fluids to which they may be exposed.
-
during a calibration, the _____ must be vented after each pressure value has been applied.
pressure sensor
-
while setting up the unit for a calibration, the ____ must be connected to the calibrator and to the instrument being calibrated.
air supply
-
instruments are calibrated to ensure that their __ accurately represents the input.
output
-
instruments should be calibrated in the following situations:
all of the above. transferring the instrument to a new control loop/following the repair to the instrument/ prior to installation.
-
information on the recommended setup for a calibration can usually be found in
manufactures instructions
-
to prevent erroneous indications, instrument ______ should be checked to ensure that they are tight and leak free.
connections
-
if the instrument under test is rated for an accuracy of plus or minus 1, the output standard selected for a calibration should ideally have a accuracy of plus or minus __.
.1
-
the test points selected for calibration should include values (at or within) _______ percent of the instruments upper and lower range values.
10
-
during an upscale check, test points should be approached form _______ .
below
-
it is unlikely that some ______ errors will be discerned in a three-point calibration check.
linearity
-
it is important to allow the ____ value to stabilize before recording the data
output
-
milliammeters are usually connected in ____with the instrument under test when they are used as output standards.
series
-
instruments should be calibrated in the following situations:
all of the above. after changing the position in which it is mounted/prior to repair of the instrument/after determining that product does not meet specifications
-
ideally, the output standard selected for a calibration should be plus or minus 0.1, if the instrument under test is rated for an accuracy of plus of minus. ____.
-
during a downscale check, test points should be approached from ____
above
-
if zero shift and span errors are revealed during a series of calibration cycles, ____ is usually corrected first
zero shift
-
___ defines the highest and lowest values of the measured variable that an instrument is designed to measure, receive, or transmit.
range
-
___ is the algebraic difference between and the upper and lower values of an instruments range.
span
-
the test points selected for calibration should include values at or within ten percent of the upper and lower ____ values
scan
-
after any required adjustments have been made, another _____ should be performed to verify the results of the adjustments.
calibration cycle
-
the following information can usually be located in the manufacturers instructions accompanying a measuring or indicating instrument.
all of the above. recommended setups/test conditions/adjustment points for zero, span, and linearity
-
a calibration _____ simulates the process variables to be measured by the instrument under test.
setup
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