Fluke 5790A, Operator'S Manual

Page: 182 / 220

5790A
Operators Manual
A-6
reliability
A measure of the probability of failure of an instrument.
repeatability
See "precision".
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 measurementsystem or device.
For a given parameter, resolution is the smallest increment that can be measured,
generated or displayed.
reversal error
Also called turnover error, the difference in output of an ac-dc transfer standard for the
same dc input but with polarity reversed. The output logged for the dc reference should
be the average of the two readings.
retrace error
For an ac-dc transfer standard, the degree of agreement of output value readings when
input is applied, removed, and reapplied over a specified time period.
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 generates a dc output signal proportional to the rms value of the input
signal. RMS sensors operate by measuring the heat generated by a voltage through a
known resistance (i.e., power); therefore, they sense true rms voltage. RMS sensors are
used to make ac-dc difference measurements.
scale
The absolute span of the reading range of a measurement device including overrange
capability.
scale error
See "gain error".
secondary standard
A standard maintained by comparison against a primary standard.
sensitivity
The degree of response of a measuring device to the change in input quantity, or a figure
of merit that expresses the ability of a measurement system or device to respond to an
input quantity.
settling time
The time it takes for a measurement device's reading to stabilize after a voltage is applied
to the input.