Offset Error - Fluke 5522A Operator's Manual

offset error

Same as zero error. The reading shown on a meter when an input value of zero is applied
is its offset or zero error.
parameters
Independent variables in a measurement process such as temperature, humidity, test lead
resistance, etc.
power factor
The ratio of actual power used in a circuit, expressed in watts, to the power which is
apparently being drawn from the source, expressed in volt-amperes.
precision
The precision of a measurement process is the coherence, or the closeness to the one
result, of all measurement results. High precision, for example would result in a tight
pattern of arrow hits on a target, without respect to where on the target the tight pattern
falls.
predictability
A measure of how accurately the output value of a device can be assumed after a known
time following calibration. If a device is highly stable, it is also predictable. If a device is
not highly stable, but its value changes at the same rate every time after calibration, its
output has a higher degree of predictability than a device that exhibits random change.
primary standard
A standard defined and maintained by some authority and used to calibrate all other
secondary standards.
process metrology
Tracking the accuracy drift of calibration and other equipment by applying statistical
analysis to correction factors obtained during calibration.
random error
Any error which varies in an unpredictable manner in absolute value and in sign when
measurements of the same value of a quantity are made under effectively identical
conditions.
range
The stated upper end of a measurement device's span. Usually, however, a measurement
device can measure quantities for a specified percentage overrange. (The absolute span
including overrange capability is called "scale.") In the 5522A, however, range and scale
are identical.
reference standard
The highest-echelon standard in a laboratory; the standard that is used to maintain
working standards that are used in routine calibration and comparison procedures.
relative uncertainty
5522A uncertainty specifications that exclude the effects of external dividers and
standards, for use when range constants are adjusted. Relative uncertainty includes only
the stability, temperature coefficient, noise, and linearity specifications of the 5522A
itself.
reliability
A measure of the "uptime" of an instrument.
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Glossary
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