Fluke 5820A, Руководство оператора

Страница: 235 / 272

A-1
Appendix A
Glossary
adc (analog-to-digital converter)
A device or circuit that converts an analog signal to digital signals.
absolute uncertainty
Uncertainty specifications that include the error contributions made by all equipment and
standards used to calibrate the instrument. Absolute uncertainty is the numbers to
compare with the UUT for determining test uncertainty ratio.
accuracy
The degree to which the measured value of a quantity agrees with the true (correct) value
of that quantity. For example, an instrument specified to +1 % uncertainty is 99 %
accurate.
apparent power
The power value obtained by simply multiplying the ac current by the ac voltage on a
circuit without consideration of any phase relationship between the two waveforms. (See
“true power” for comparison.)
assert
To cause a digital signal to go into a logic true state.
af (audio frequency)
The frequency range of human hearing; normally 15 - 20,000 Hz.
artifact standard
An object that produces or embodies a physical quantity to be standardized, for example
a Fluke 732A dc Voltage Reference Standard.
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.