Glossary
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National Instruments Corporation
G-9
ppm
parts per million
pu
pull up
Q
quantization error
the inherent uncertainty in digitizing an analog value due to the finite
resolution of the conversion process
R
referenced single-ended
configuration
RSE—all measurements are made with respect to a common reference
measurement system or ground; also called a grounded measurement
system
relative accuracy
a measure in LSB of the accuracy of an ADC. It includes all non-linearity
and quantization errors. It does not include offset and gain errors of the
circuitry feeding the ADC.
resolution
the smallest signal increment that can be detected by a measurement
system. Resolution can be expressed in bits, in proportions, or in percent
of full scale. For example, a system has 12-bit resolution, one part in
4,096 resolution, and 0.0244% of full scale.
ribbon cable
a flat cable in which the wires are lined up, not bunched together
rms
root mean square—the square root of the average value of the square of the
instantaneous signal amplitude; a measure of signal amplitude
RSE
See
referenced single-ended configuration.
S
s
seconds
S
samples
S/s
samples per second—used to express the rate at which a DAQ device
samples an analog signal
sample counter
the clock that counts the output of the channel clock, in other words, the
number of samples taken. On devices with simultaneous sampling, this
counter counts the output of the scan clock and hence the number of scans.
