Fluke 5820A, Operator'S Manual

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5820A
Operators Manual
A-6
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
5820A 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 5820A
itself.
reliability
A measure of the “uptime” of an instrument.
repeatability
The degree of agreement among independent measurements of a quantity under the same
conditions.
resistance
A property of a conductor that determines the amount of current that will flow when a
given amount of voltage exists across the conductor. Resistance is measured in ohms.
One ohm is the resistance through which one volt of potential will cause one ampere of
current to flow.
resolution
The smallest change in quantity that can be detected by a measurement system or device.
For a given parameter, resolution is the smallest increment that can be measured,
generated, or displayed.
rf (radio frequency)
The frequency range of radio waves; from 150 kHz up to the infrared range.
rms (root-mean-square)
The value assigned to an ac voltage or current that results in the same power dissipation
in a resistance as a dc current or voltage of the same value.
rms sensor
A device that converts ac voltage to dc voltage with great accuracy. RMS sensors operate
by measuring the heat generated by a voltage through a known resistance (i.e., power);
therefore, they sense true rms voltage.
scale
The absolute span of the reading range of a measurement device including overrange
capability.