Non-Destructive Coating Thickness Measuring Principles
1) Magnetic Induction Priciple:
The Phase II PTG series of Coating Thickness Gauges 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 Gauges 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.
NOTE: All PTG series Coating Thickness Gauges are inspected and calibrated using the Two-Point Calibratiuon procedure prior to shipment.
1) One-Point Calibration:
This procedure is accomplished by "Zeroing" the gauge 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 gauge on one of the supplied substrate samples (steel/aluminum) and then placing one of the calibrated "foils" on that substrate and calibrating the gauge 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 gauge will be at its most accurate when testing your own coated samples. This is the same method used to calibrate every gauge prior to shipment.
3) Frequency of Calibration:
Once the PTG series of Coating Thickness Gauge 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 gauge 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 gauge.