Rockwell Automation 1441-PEN25-Z Enpac 2500 Data Collector - Manual (Page 319)

Rockwell Automation Publication GMSI10-UM002D-EN-E - August 2012 319
Glossary
process (DC) voltage measurement A single valued measurement taken directly from a DC voltage output. Similar to
a process measurement; however you directly measure the value instead of
entering it with the data collector keypad.
Quickload list A list of measurement definitions to be loaded into a data collector. Emonitor
builds and saves Quickload lists as load files so that they do not have to be rebuilt
every time before loading into the data collector.
resolution The accuracy of something based on the number of discrete values used to define
it. One example is the resolution of a spectrum measurement. This refers to the
number of spectral lines that are combined to display the spectrum data. A higher
resolution results in a clearer image due to more discrete values defining the
object.
route See list.
signature A signature can be either a time or a spectrum measurement. It is a general term
used for multi-valued data, as opposed to single-valued data such as a magnitude
or a process measurement.
spectral line A spectral line is an individual discrete frequency in a spectrum measurement. A
spectral line is sometimes called a ‘bin,‘ a ‘delta f,‘ a ‘line,‘ or a ‘line of resolution.‘
spectrum alarm Also called narrowband alarm. It defines the safe operating boundary for
spectrum data from a piece of equipment.
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 computers 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.