DeFelsko PosiTector UTG v.3.1 Full Manual User Manual

Page 42

Gage displays -.-- (dashed lines) when measuring on an
smooth uncoated surface in multiple echo mode
See UTG M probes note on pg. 5

Gage is coupled, but not measuring
On smooth, uncoated metal surfaces the Gage (in multiple echo
(ME) mode) may occasionally be unable to give a measurement
result even when the "coupled" symbol appears. Use additional
couplant and lighter pressure on the probe when measuring.
Switching the Gage to SE mode (pg. 16) will also help produce a
steel-only thickness measurement. Alternatively, laying a plastic
shim on the surface with couplant applied to both sides to simu-
late a painted surface will help produce a steel-only thickness
measurement in ME mode.

When measuring non-parallel surfaces, ME mode does not
display a reading
Measurement accuracy may be diminished when ME mode is
used to measure a part that has non-parallel surface and back
walls. A distorted echo or no echo at all may result. Switch to SE
mode (pg. 16) and retry.

Thickness values are repeatable, but seem incorrect
1. When measuring thick, hard coatings on thin metal, ME and SE
modes may both give improper results. This unusual condition
results in many gages interpreting the thick coating as the metal
and the thin metal as a coating on the backside. The Gage
therefore displays the thickness of the coating using the velocity
calibration for the metal. This application may not be measurable.

2. The Cal Settings property may be incorrect. For best accuracy
the Gage must be set to the correct sound velocity for that
material (see pg.11).

3. Too much loose rust or scale may be present on the surface.
Scrape away loose material with a wire brush or scaper and apply
sufficient couplant. In extreme cases, rotary sanders or grinding

UTG M multiple echo (ME) probes only