Section 6 – Maintenance
6-5
Troubleshooting notes
If a fault is suspected in the probe, the following items may
be checked to verify its failure.
Make sure the probe and the connection cable are 1.
properly mounted and secured.
Check the output of the driver using an oscilloscope or 2.
other similar general purpose test equipment.
Check the performance of power supplies, or other in-3.
line accessories.
Check the continuity and insulation ability of any 4.
interconnecting cables using a Meg ohmmeter. Be
aware that a non-wrapped connector or the abrasion of
jacket material on coaxial cables could cause the shield
to short to ground which creates possible ground loop
problems.
Check the performance of any readout devices used 5.
with the probe.
Change out probe to a known good one to see if 6.
problem is probe or driver.
If the output of the probe is incorrect, it should be replaced.
A loose or dirty cable connection can cause erratic output
of the probe. Make sure the cable connections are clean
and tight.
Repairs
Eddy current probes produced by SKF are not normally
repairable except for the end connector.
Caution: Do not repair probe cables or extension cables by
cutting the cable and replacing failed connectors.
The probe and cable are cut to a specific length to produce
a “tuned” circuit. Changing the length of a cable will
seriously affect the accuracy of its measurements.
Probe gap voltage test setup
Connect -24 to -30 volts to driver 1.
(CMSS 500-PWRSUP).
Connect driver output to digital voltmeter.2.
Connect probe and extension cable to driver.3.
Adjust probe into machine to reach specified voltage.4.
Tighten lock nut on probe to maintain proper 5.
adjustment.
Figure 6-7. Probe gap voltage test setup.
To gap a CMSS 65-xxx-xx-xx-10 Probe, use a •
CMSS 958-xx-040 Extension Cable and a CMSS 665
Driver.
To gap a CMSS 68-xxx-xx-xx-10 Probe, use a •
CMSS 958-xx-040 Extension Cable and a CMSS 668
Driver.
To gap a probe at 40 mils (1.0 mm), adjust the probe for •
a -8.00 volt reading on the digital voltmeter.
To gap a probe at 50 mils (1.2 mm), adjust the probe for •
a -10.00 volt reading on the digital voltmeter.
System sensitivity is 200 mV/mil (8 mV/µm) for both •
systems.
To Next Page
Loading...
