DeFelsko PosiTector UTG v.2.2 - Manual (Page 6)

6
Surface Conditions Surface Conditions
Ultrasonic measurements are affected by the
condition, roughness and contour of the surface to
be tested.
Measurement results may vary on coarse surfaces.
Where possible, it is recommended to seat the
transducer on a smooth flat surface that is parallel to
the opposite side of the material.
On rough surfaces, the use of a generous amount of
couplant minimizes the surface effects and serves to
protect the transducer from wear, particularly when
dragging the probe across a surface.
On smooth, uncoated metal
surfaces the Gage (in 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. Alternatively, laying a plastic shim on the
surface with couplant applied to both sides to
simulate a painted surface will help produce a steel-
only thickness measurement (multiple-echo mode).
Switching the Gage to SE mode (see pg.15) will also
help produce a steel-only thickness measurement.
Zero Menu Option Zero Menu Option
The PosiTector UTG probe can be "zeroed" to com-
pensate for temperature and wear. This action is not
required when operating in ME (multiple-echo) mode
except when the Gage is new and after a Reset (pg.
16). However it ensures best accuracy when operat-
ing in SE (single-echo) mode. Therefore it is a good
idea to "zero" the probe before each work shift and
when the temperature of the part changes. During
zeroing, it does not matter what the current velocity
setting is.
Zero
ME Mode Note: