PRÜFTECHNIK VIBXPERT II - Starting the Measurement and Displaying the Shaft Centerline Plot; Static Shaft Position; Sensor Arrangement

5-13
VIBXPERT II 05.2012
Starting the measurement and displaying the shaft centerline plot
• Clickonthemeasurementtaskiconandthenon'Start'(seep.5-6).
During data collection, the values for the DC component are dis-
playedinthemeasurementdatadialogwindow(seep.5-7).
• Aftermeasurement,presstheFkeyandclickon'Shaftcenterline'.
The shaft centerline plot appears (see below).
Static shaft position
By default, the DC component at the smallest rpm defines the static
shaft position in the shaft centerline plot. The static shaft position can
also be set after measurement using other methods:
• PresstheMENUkeyintheresultsscreen.
• Select'Shaftcenterline'andclickon'Getshaftrestposition'.
• Selectoneofthefollowingmethods:
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current cursor: Cursor position indicates the rest position.
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enter manual: Enter the coordinates for every channel.
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measure:Usethe'Staticshaftposition'measurementtask.
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choose from file:Importfroma'Staticshaftposition'resultle.
Sensor arrangement
The arrangement of the sensor relative to the direction of rotation in-
fluences the position and orientation of the shaft displacement in the
diagram. Because the direction of the shaft displacement with respect
to the direction of rotation is a characteristic of certain fault types in
journal bearings, the correct sensor arrangement in the diagram is im-
portant. If necessary, the arrangement of the sensors and the direction
of rotation can be mirrored:
• PresstheMENUkey.
• Select'Shaftcentreline'andclickon'Fitsensoradjustment'.
• Inthenextwindow(sensorgeometry,atright),clickon'FlipA-B'.
Shaft bearing - does not contain abso-
lute bearing dimensions
Sensor A and B at 90° to each other
Direction of shaft rotation
Shaft centerline displacement during
measurement
rpm at cursor position
Shaft centerline plot
Channel A Channel B
Static shaft position
'Advanced' tab
Mirroring the sensor arrangement
Measurement tasks
Shaft rest position
Methods for reading in the rest position