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Glossary
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National Instruments Corporation
G-7
N
NI-DAQ
The driver software needed in order to use NI E/M Series DAQ devices and
SCXI components.
noise
An undesirable electrical signal—Noise comes from external sources such
as AC power lines, motors, generators, transformers, fluorescent lights,
soldering irons, CRT displays, computers, electrical storms, welders, radio
transmitters, and internal sources such as semiconductors, resistors, and
capacitors. Noise corrupts signals you are trying to measure.
nonlinearity
For an amplifier, a measure of the maximum output deviation from an ideal
linear response in units of percent relative to full scale. The ideal linear
response is taken to be a straight line on a plot of measured output voltage
to measured input voltage with the ends of the line connecting the extremes
of the plot at the full-scale limits.
O
offset error
The output of a system with a zero-volt input.
offset null
compensation
The provision in strain-gauge signal conditioning hardware to remove the
unwanted offset voltage present at the output of a strain-gauge bridge when
no strain is applied.
overvoltage protection
Maximum voltage that does not cause hardware damage.
P
passband
The range of input frequencies that are passed to the filter output without
attenuation.
Poisson’s ratio
The negative ratio of transverse strain to longitudinal (axial) strain.
pole
A term used to describe the quality of a lowpass filter. In general, the more
poles a lowpass filter has, the better it attenuates frequencies beyond the
cutoff frequency.
port
A digital port consisting of multiple I/O lines on a E/M Series DAQ device.
pp
Peak to peak.