PTG Coating Thickness Gauges
Non-Destructive Coating Thickness Measuring
Principles
1) Magnetic Induction Priciple:
The Phase II PTG series
of Coating Thickness Gages utilize this non-destructive
priciple when measuring coatings on ferro-magnetic
substrates such as Steel and Iron. The coatings must be
non-magnetic such as; paint, enamel, aluminum, chrome,
copper and brass.
2) Eddy-Current Priciple:
The Phase II PTG series
of Coating Thickness Gages utilize this non-destructive
priciple when measuring coatings on non-magnetic
substrates such as; Aluminum, Aluminum Alloys, bronze,
copper, brass tin and rustproof weak magnetic steels.
The coatings must be electrically insulating such as;
paint, enamel, plastics, anodized coatings and ceramics.
Calibration Procedures
NOTE:
All PTG series Coating Thickness
Gages are inspected and calibrated using the Two-Point
Calibratiuon procedure prior to shipment.
1) One-Point Calibration:
This procedure is accomplished by "Zeroing" the
gage on an uncoated version of the sample that you will
be checking the coating thickness on. To accomplish this
calibration, you will need to follow the simple
calibration procedure that is explained in the operation
manual. Although this is an accurate method for
calibration, it is not as accurate as using the two
point calibration.
2) Two-Point Calibration:
This procedure is accomplished by "zeroing" the
gage on one of the supplied substrate samples
(steel/aluminum) and then placing one of the calibrated
"foils" on that substrate and calibrating the gage to
match the known thickness of the foils. It is best to
use the foil that is closest to the actual known
thickness of your own samples to be tested. This is a
very simple procedure that is explained in the operation
manual. By using the two-point calibration procedure,
you are making sure that the gage will be at its most
accurate when testing your own coated samples. This is
the same method used to calibrate every gage prior to
shipment.
3) Frequency of Calibration:
Once the PTG series of Coating Thickness Gages
have been calibrated, the parameters are saved in the
memory and the calibration procedure does not need to be
repeated.
We do recommed that after numerous hours of operation or
if the gage has not been used for a few days you should
check the accuracy using the same calibrated
substrate/foil combination previously used to calibrate
the gage.
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