National Instruments BNC-2140 User Manual page 37

Glossary
Shannon Sampling
Theorem
SNR
source impedance
SS
S/s
system noise
T
THD
THD+N
transducer
transducer excitation
U
unipolar
update rate
BNC-2140 User Manual
a law of sampling theory stating that if a continuous bandwidth-limited
signal contains no frequency components higher than half the frequency
at which it is sampled, then the original signal can be recovered without
distortion
signal-to-noise ratio—the ratio of the overall rms signal level to the rms
noise level, expressed in decibels
a parameter of signal sources that reflects current-driving ability of voltage
sources (lower is better) and the voltage-driving ability of current sources
(higher is better)
simultaneous sampling—a property of a system in which each input or
output channel is digitized or updated at the same instant
samples per second—used to express the rate at which a DAQ board
samples an analog signal
a measure of the amount of noise seen by an analog circuit or an ADC when
the analog inputs are grounded
total harmonic distortion—the ratio of the total rms signal due to harmonic
distortion to the overall rms signal, in decibel or a percentage
signal-to-THD plus noise—the ratio in decibels of the overall rms signal to
the rms signal of harmonic distortion plus noise introduced
See sensor
a type of signal conditioning that uses external voltages and currents to
excite the circuitry of a signal conditioning system into measuring physical
phenomena
a signal range that is always positive (for example, 0 to +10 V)
the number of output updates per second
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