PRÜFTECHNIK VIBXPERT II - Runup; Coastdown; Runup; Coastdown; A. Selecting the Measurement Task

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VIBXPERT II 05.2012
Measurement tasks
Runup / Coastdown
The runup and coastdown curves record the changes in the vibration
behavior of the machine when it starts up or shuts down. This analy-
sis function can be used to determine the resonance frequencies of a
machine. The following types of measurement are available for this
purpose:
- Phase vector (amplitude and angle), dependent on the RPM
- Spectrum,dependentontheRPM
- Overall value, dependent on the RPM
Runup
Measurement is started before the machine is switched on. VIB XPERT
records the current RPM and automatically begins with measure-
ment as soon as the selected start RPM is exceeded. Measurement is
stopped when the stop RPM is reached.
Coastdown
Measurement is started while the machine is running at the operating
RPM. VIBXPERT then begins to measure the RPM continuously. Once
you have switched the machine off and it drops below the selected
start RPM, VIBXPERT automatically starts recording the data. Mea-
surementstopsoncetheselectedstopRPMisreached.Startandstop
RPMsaredenedinthemeasurementsetup(seep.3-22).
A. Selecting the measurement task
The measurement tasks for a runup / coastdown curve are located in
the'Advanced'tab.Themeasurementtypes'Phase-RPM'and'Spectra
-RPM'areassignedataskicon;the'OverallValue-RPM'measure-
ment type has its own icon.
Left:
Selecting the
measurement task
Right:
Starting the measurement
Overall value - RPM
Runup / Coastdown
Overall values (RPM)
Runup / Coastdown
Phase, spectra (RPM)