PRÜFTECHNIK VIBTOOL - RPM Measurement

VIBTOOL 02.2009
43
RPM measurement
VIBTOOL is an accurate non-contact rpm measurement
instrument, thanks to the new and patented contrast
marker method.
Normal non-contact methods of RPM measurements use
the reflection principle. However, the contrast sensor built
into VIBTOOL does not use a power-consuming light beam
and, as a result, no reflective foil. RPM measurements,
therefore, can be undertaken without having to stop the
machine to be measured. The optical trigger inside VIB-
TOOL is capable of recognizing a change in contrast (from
light to dark or from dark to light) of the surface towards
which it is pointed. You simply locate a mark on the shaft
or rotor, such as an oil mark, and point VIBTOOL in that
direction. VIBTOOL then adjusts itself accordingly to the
contrast between the oil mark and the background. Each
time the rotor contrast mark passes by, VIBTOOL registers
this as an electric pulse which it uses to calculate the RPM
of the machine and then display it on the screen.
In cases where the contrast is not great enough, simply use
a black felt-tip pen,
or white corrector-fluid (e.g. Tippex
®
)
to mark the rotor to obtain a good contrast. Rotors with
larger diameters can also be measured.
Do not use reflective tape as a contrast mark!
10- 20cm
M
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Note
RPM measurement