PRÜFTECHNIK VIBXPERT II - C.1 Overall Value - RPM Measurement Type; C.2 Spectrum - RPM Measurement Type

5-8
VIBXPERT II 05.2012
Measurement tasks
C. Supplementary information
C.1 'Overall Value - RPM' measurement type
This type of measurement records the progression of the character-
istic overall vibration values relative to the RPM. Points of resonance
are indicated by RPMs with increased vibration amplitudes.
TheResultsscreendisplaysthepathoftheRMSvalueintheupper
diagram;oneofthethreepeakvalues(0-p,p-p,crestfactor)canbe
displayed in the lower diagram:
• Todothis,presstheFkeyandselecttherespectivecharacteristic
value (see below).
C.2 'Spectrum - RPM' measurement type
This type of measurement records the spectra while the machine RPM
is changing. In this way, the progression of the RPM-dependent vibra-
tion components in the spectrum can be tracked and the points of
resonance can be identified.
To start the measurement, the following condition must be fulfilled:
f
max.
> 4x n
max.
(maximum rpm)
The results screen always displays two consecutive spectra of the
recorded series (see below). Use the '+/-' key to scroll forwards and
backwards. The current number and the associated RPM for the spec-
trum are displayed at the top left of the diagram. To scroll in only one
of the two diagrams, fix the display in the other diagram:
• PresstheMENUkeyandclickon'FixDiagram>below(orabove)'.
A better overview is provided by displaying the spectra in a waterfall
diagram(seealsop.4-13):
• PresstheMENUbuttonandclickon'Waterfalldiagram'.
Runup / Coastdown:
Overall value - RPM
selecting peak value
Spectrum - RPM
Individual display
Spectrum - RPM
Waterfall diagram