4 Measuring Methods of Coating Thickness Gauge

Coating thickness gauges are a type of thickness gauge. They are known to non-destructively measure the thickness of non-magnetic coatings (such as aluminum, chrome, copper, enamel, rubber, and paint) and non-magnetic coatings on magnetic metal substrates (such as steel, iron, alloys, and hard magnetic steel) Thickness of non-conductive coatings (e.g. enamel, rubber, paint, plastic) on magnetic metal substrates (e.g. copper, aluminum, zinc, tin). What is the measurement method of the coating thickness gauge?

Magnetic Thickness Gauge

It is suitable for non-magnetic layer thickness measurement on magnetic conductive materials. Magnetic materials are generally: steel, iron, silver, and nickel. This method has high measurement accuracy.

Eddy Current Thickness Gauge

Eddy current thickness gauges are suitable for measuring the thickness of non-conductive layers on conductive metals, but the accuracy is relatively low.

Ultrasonic Thickness Gauge

Actually, the ultrasonic thickness gauge is suitable for measuring the thickness of multi-layer coatings or occasions where the above two methods cannot be measured. But generally, the price is slightly expensive and the measurement accuracy is not high.

Electrolytic Thickness Gauge

This method is different from the above three thickness gauge. Electrolytic thickness gauges are not non-destructive testing, they need to destroy the coating, and the accuracy is not high. It is more difficult to measure than others.

Radiographic Thickness Gauge

Such thickness gauges are very expensive and are only suitable for some special occasions.

Notes for measuring paint thickness gauge

• During the test, it should be noted that the metal magnetism and surface roughness of the standard piece should be similar to the test piece.
• Keep the side head perpendicular to the surface of the sample during measurement.
• Pay attention to the critical thickness of the base metal when measuring. If it is greater than this thickness, the measurement will not be affected by the thickness of the base metal.
• Pay attention to the curvature of the specimen when measuring. Unreliable measurements on curved specimen surfaces
• Before measuring, pay attention to whether other electrical equipment around will generate a magnetic field. If so, it will interfere with the magnetic thickness measurement method.
• When measuring, be careful not to measure at the inner corner and near the edge of the test piece, because the general thickness gauge is very sensitive to the sudden change of the surface shape of the test piece.
• Keep the pressure constant during measurement, otherwise, it will affect the measurement reading.
• When testing, pay attention to the direct contact between the instrument probe and the test piece, so the ultrasonic thickness gauge removes the attached material on the opposite side.