Rockwell Automation 441-PEN25 Enpac Ex Data Collector - Manual (Page 136)

Publication GMSI00-UM001A-EN-E - February 2005
Glossary 130
spectrum measurement
A measure of amplitude versus frequency, typically vibration for monitoring
systems. Spectrum measurements are useful for identifying the contribution of
individual components (bearings, fans, gears, etc.). It is much easier to separate
elements of vibration in the frequency domain than in the time domain.
spectrum plot
A spectrum plot is a graph of amplitude versus frequency. Usually the
amplitude is a measure of the acceleration, velocity, or displacement at that
frequency.
storage specification
The storage specification controls when to collect a measurement, and how
long to store it on the computer’s hard disk. You can use the storage
specification to force the collection and storage of a measurement at a given
time interval, or if a measurement exceeds an alarm.
tachometer
A device for measuring the speed of rotation of a machine or component.
time waveform measurement
A measure of time along the horizontal axis and amplitude along the vertical
axis (similar to oscilloscope readings). It is easy to see the vibration amplitude
and general shape of the signal in a time waveform measurement. They are
useful for identifying simple vibration signals and viewing impulsive type
signals.
time waveform plot
A time waveform plot is a graphical display of amplitude versus time for a
single measurement.
transducer
A transducer is a device for making measurements. These include
accelerometers, velocity pickup, displacement probes, and temperature sensors.
transducer specification
A transducer specification defines the characteristics of a transducer. These
include the transducer name, type, base unit, and calibration.