PRÜFTECHNIK VIB 5.300 EX Series, Operating Instructions Manual

Page: 132 / 172

5-16
VIBXPERT 11.2010
Measurement tasks
filtered unfiltered
* The movement of the shaft axis while
the machine is running up / coasting
down is recorded with a shaft center-
line plot (see p. 5-12).
Channel A
(VIB 6.640)
Channel B
(VIB 6.640)
Keyphaser
(VIB 6.631)
F ESC
MEN
U HEL
P
Typical installation
with inductive displacement sensors
Orbit
The movement of the shaft axis* at constant speed is measured with
two non-contact sensors that are installed in an angular distance of
90 °.
This enables identification of machine faults and damage to the shaft
that become apparent in the vibration behavior of the shaft and
directly affect the path of the shaft (e.g. unbalance, misalignment,
shaft crack, rotation fault - for more details, see VDI 3839 Sheets 1
and 2). When using 'filtered orbit', the signal is processed in an order
filter and therefore requires a keyphaser to provide a reference.
A typical measurement installation is shown in the following figure:
- The two displacement sensors are mounted in a single measure-
ment plane at an angular displacement of 90° on the machine.
If this angular displacement is not possible, you can mount the
sensors at any angular displacement between 5° and 175°. Then
enter the angular displacement in the measurement setup ('Sen-
sor angle' parameter). However, measurement accuracy is limited
when the sensor angle
≠
90°.
- The sensor on channel A defines the X direction and the 0°
position.
- The keyphaser is mounted in the 0° position.
- Note the setting of the active edge for the trigger signal (see:
Keyphaser Menu/Device Setup, p. 2-23).
The procedure for an orbit measurement is described in the
following standards: ISO 7919, ISO 10817-1, VDI 3839 Sheet1.
A description of the measurement procedure with VIBXPERT can
be found in the Technical Information CM # 18 'Analysis of radial
shaft movement in journal bearings’ - available free on our website.

Note