Polytec MSA-600, Operating Instructions Manual

Page: 79 / 99

5-5
5 Troubleshooting
5.7 Measurement Signal is Faulty
For technical reasons the sensor head reacts very sensitive to background
vibration. Unfavorable positioning of cables can also cause electrically
induced interferences.
Mechanical
vibrations
Distortions caused by background vibrations are mainly observed in the
frequency range 1 Hz to 1 kHz. They are seen as peaks of different widths in
the spectrum. The inherent noise peaks at the resonant frequencies of the
Piezo scanners are unavoidable and are found between 2 and 4 kHz. Parts of
the sensor head can also cause resonance vibrations.
To extensively attenuate mechanical vibrations, position the sensor head on a
solid, vibration-isolated base.
Electrical
interference
Under some circumstances, unfavorable cabling of the system can also
induce distortions.
To prevent electrical interferences, proceed as follows:
•
Connect all devices of the measurement system to a common multiple
mains socket.
•
Do not install measurement and control cables close to mains cables.
5.8 Measurement Takes an Unusually Long Time
After you have changed the settings regarding the bandwidth extension
(none, BWX1, BWX2), the first measurement may take unusually long. This is
not a malfunction. All subsequent measurements do not require a longer
measurement time.