Fluke 5500A Operator's Manual page 382

5500A
Operator Manual
thermocouple
Two dissimilar metals that, when welded together, develop a small voltage dependent on
the relative temperature between the hotter and colder junction.
traceability
The ability to relate individual measurement results to national standards or nationally
accepted measurement systems through an unbroken chain of comparisons, i.e., a
calibration "audit trail."
Measurements, measurement systems or devices have traceability to the designated
standards if and only if scientifically rigorous evidence is produced in a continuing basis
to show that the measurement process is producing measurement results for which the
total measurement uncertainty relative to national or other designated standards is
qualified.
transfer error
The sum of all new errors induced during the process of comparing one quantity against
another.
transfer standard
Any working standard used to compare a measurement process, system, or device at one
location or level with another measurement process, system, or device at another
location or level.
transport standard
A transfer standard that is rugged enough to allow shipment by common carrier to
another location.
true power
The actual power (real power) used to produce heat or work. Compare to 'apparent
power."
true value
Also called legal value, the accepted, consensus, i.e., the correct value of the quantity
being measured.
uncertainty
The maximum difference between the accepted, consensus, or true value and the
measured value of a quantity. Uncertainty is normally expressed in units of ppm (parts
per million) or as a percentage.
units
Symbols or names that define the measured quantities. Examples of units are: V, mV, A,
kW, and dBm. See also "SI System of Units."
UUT (Unit Under Test)
An abbreviated name for an instrument that is being tested or calibrated.
var
Symbol for voltampere reactive, the unit of reactive power, as opposed to real power in
watts.
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