Fluke 5502A, Operator'S Manual

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Glossary
A
A-3
floor
The part of the uncertainty specification of an instrument that is typically a set offset plus
noise. Floor can be shown as units, such as microvolts or counts of the least significant
digit. For the 5502A, the floor specification is combined with set range errors in one term
to find total uncertainty.
full scale
The maximum indication of a range of a meter, analog-to-digital converter, or other
measurement device, or the maximum attainable output on a range of a calibrator.
gain error
Same as scale error. Scale or gain error results when the slope of the response curve of
the meter is not exactly 1. A meter with only gain error (no offset or linearity error), will
read 0 V with 0 V applied, but something other than 10 V with 10 V applied.
ground
The voltage reference point in a circuit. Earth ground is a connection through a ground
rod or other conductor to the earth, usually accessible through the ground conductor in an
ac power receptacle.
ground loops
Undesirable currents induced when there is more than one chassis ground potential in a
system of instruments. Ground loops can be minimized by connecting all instruments in a
system to ground to one point.
guard
See “voltage guard”.
harmonics
A waveform that is an integral multiple of the fundamental frequency. For example, a
waveform that is two times the frequency of a fundamental is called the second harmonic.
IPTS-68
Refers to the International Provisional Temperature Standard (1968), replaced by the
International Temperature Standard (1990). This specifies the definition of the
°
C
temperature standard.
ITS-90
Refers to the International Temperature Standard (1990), which replaced the International
Provisional Temperature Standard (1968). This specifies the definition of the
°
C
temperature standard.
International Systems of Units
Same as “SI System of Units,” the accepted system of units. See also “units,” “base
units,” and “derived units.”
legal units
The highest echelon in a system of units, for example the U.S. National Bureau of
Standards volt.