Classification of measurement methods of coating thickness gauges

The measurement methods of coating thickness gauges are mainly divided into the following types:

1. Magnetic thickness measurement method: suitable for measuring the thickness of non-magnetic layers on magnetic materials. Magnetic materials are generally: steel, iron, silver, nickel. This method has high measurement accuracy.

2. Eddy current thickness measurement method: suitable for measuring the thickness of non-conductive layers on conductive metals. This method has lower accuracy than the magnetic thickness measurement method.

3. Ultrasonic thickness measurement method: At present, there is no such method in China to measure the thickness of coatings and plating layers. Some foreign manufacturers have such instruments, which are suitable for measuring the thickness of multi-layer coatings and plating layers or occasions where the above two methods cannot be measured. But the price is generally expensive and the measurement accuracy is not high.

4. Electrolytic thickness measurement method: This method is different from the above three methods. It does not belong to non-destructive testing and requires the destruction of coatings and plating layers. The general accuracy is not high. It is more troublesome to measure than the other methods.

5. Radioactive thickness measurement method: This instrument is very expensive (generally more than 100,000 RMB), suitable for some special occasions.

Of course, the most commonly used thickness measurement methods for coating thickness gauges in China are magnetic thickness measurement method and eddy current thickness measurement method.