Fluke 5790B Service Manual page 136

5790B
Service Manual
AC-DC Transfer
The process of comparing an AC voltage to a known DC voltage, thereby
transferring the low uncertainty of the DC voltage to the AC voltage. The 792A
can be used to perform two different types of AC-DC transfers:
1. An AC measurement
2. An AC-DC difference measurement
In a measurement, the transfer standard is used to determine absolute RMS
voltage level. In an AC-DC difference measurement, the transfer standard is a
reference that tests the and DC response of another transfer standard. The goal
of a measurement is to determine the error of the source or voltmeter under test.
The goal of an AC-DC difference measurement is a value called the "AC-DC
difference", which is positive when more voltage than DC voltage is required to
produce the same output in the transfer standard under test.
AC-DC Difference
A measurement of an AC-DC transfer device's accuracy. The AC-DC difference
is a transfer device's error when it compares a DC voltage to the same RMS
voltage. A positive AC-DC difference indicates that more alternating than direct
voltage is required to produce the same reading.
Base Units
Units in the SI system that are dimensionally independent. All other units are
derived from base units. The only base unit in electricity is the ampere.
Buffer
1. An area of digital memory for temporary storage of data.
2. An additional amplifier stage to reduce output impedance levels.
Burden Voltage
The maximum sustainable voltage across the terminals of a load.
Calibration
The comparison of a measurement system or device of unknown accuracy to a
measurement system or device of known and greater accuracy to detect or
correct any variation from required performance of the unverified measurement
system or device. Also see "verification" and "traceability".
Calibration Constant
A coefficient that is applied manually or automatically to adjust the output or
reading of an instrument.
Calibration Curve
A smooth curve drawn through a graph of calibration points.
Calibration Interval
The interval after which calibration must occur to maintain the performance of an
instrument as stated in its specifications.
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