Glossary
©
National Instruments Corporation
G-3
DAQMeter DAQCard-4050 User Manual
C
C
Celsius
CMRR
common-mode rejection ratio—a measure of an instrument’s ability to
reject interference from a common-mode signal, usually expressed in
decibels (dB)
continuity
the measure of the ability of a material to conduct electricity
conversion device
device that transforms a signal from one form to another. For example,
analog-to-digital converters (ADCs) for analog input, digital-to-analog
converters (DACs) for analog output, digital input or output ports, and
counter/timers are conversion devices.
conversion time
the time required, in an analog input or output system, from the moment
a channel is interrogated (such as with a read instruction) to the moment
that accurate data is available
coupling
the manner in which a signal is connected from one location to another
CPU
central processing unit
crest factor
the ratio of the peak value of the signal to the RMS value of the signal
CSM
current shunt module
D
DAQ
data acquisition—(1) collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and inputting them to a
computer for processing; (2) collecting and measuring the same kinds
of electrical signals with A/D and/or DIO boards plugged into a
computer, and possibly generating control signals with D/A and/or DIO
boards in the same computer
dB
decibel—the unit for expressing a logarithmic measure of the ratio of
two signal levels: dB=20log10 V1/V2, for signals in volts
DC
direct current
