DeFelsko PosiTector 200 v.1.2 User Manual

Page 6

Page 6

Set Gates Option

Although the PosiTector 200 is designed to measure the thickness of polymer
coatings in the thickness range of 25 to 1000 microns (1 to 40 mils) circumstances
may require the user to restrict this measuring range using Gates.

Gate A sets the minimum thickness limit and Gate B the maximum limit. The
default Gate A setting is 25 microns (1 mil). The default Gate B setting is 1000
microns (40 mils). These defaults can be restored at any time by performing a
gage RESET (pg.10).

For most applications these Gate values do not have to be adjusted. But some
conditions may exist in the user's application that cause the Gage to display very
low or non-repeatable readings. These conditions include…

·rough or textured coatings
·hard (dense) coatings
·coatings applied in multiple layers
·coatings applied on a very thin, hard substrate

Important: When measuring, the Gage finds the most distinct interface within the
two Gate settings. If the coating thickness is outside this range, incorrect or
dashed readings may occur. The PosiTector 200 interprets the largest “echo”
within the gates as the coating/substrate echo.

Gate A

Gate A should be high enough to prevent
the Gage from reading surface roughness.
Unusually low readings indicate that Gate
A may be set too low.

The probe must be periodically zeroed using the ZERO menu option to compen-
sate for both extreme temperature and probe wear effects. Before using, allow the
probe to reach ambient temperature. Wipe the probe clean of couplant.

If measurements will be made in extreme hot or cold temperatures, it is recom-
mended to ZERO the probe in the working environment.

If measurements will be made on rough substrates, it is recommended to period-
ically ZERO the probe to compensate for wear.

Zero Menu Option