DeFelsko PosiTector UTG v.2.2 - Manual (Page 17)

17
Troubleshooting Troubleshooting
Some common reports received by our Service
Department along with possible causes. Most condi-
tions however can be cleared with a Reset (pg. 16).
Probe continues to measure after lifted from
surface
Wipe away any excess couplant on probe tip.
Gage fails to power down
Ensure the probe is clean and free of couplant. The
Gage will not turn off if coupled symbol is
displayed on LCD.
Gage is coupled, but not measuring
See Surface Conditions, pg. 6.
The surface temperature of the test piece should not
exceed (150° C / 300° F)
Application Notes Application Notes
Measuring on hot surfaces
Measurements taken at higher temperatures (above
100° C / 212° F) require special consideration. Both
material sound velocity and probe zero will change
with temperature. For maximum accuracy at high
temperatures, adjustment should be performed
using a material of known thickness heated to the
temperature where measurements are to be
performed. The probe should remain on the surface
only as long as it takes to get a measurement.
Gage readings appear to be double the expect-
ed thickness
This sometimes occurs near the minimum measur-
ing range of the instrument (0.100" or 2.5mm). The
first return echo is unmeasurable, so the gage meas-
ures the second return echo. The resultant calcula-
tion is double the actual thickness.