How to efficiently use a coating thickness gauge
Non-destructive testing technology is a subject with strong comprehensiveness in theory and a promising future that attaches great importance to practical links. It involves many aspects such as physical properties of materials, product design, manufacturing process, fracture mechanics and finite element calculation.
In the chemical industry, electronics, electric power, metal and other industries, in order to achieve the protection or decoration of various materials, methods such as spraying non-ferrous metal coverage, phosphating, and anodic oxidation treatment are usually used, so that coatings, platings, coatings, etc. appear. Layers, laminates or chemically generated films, we call them "cladding".
The thickness measurement of the cladding has become the most necessary process for the users in the metal processing industry to carry out the quality inspection of the finished products. It is an essential means for products to meet safety standards. At present, the thickness of the coating has been generally measured according to the unified international standard at home and abroad. The selection of methods and instruments for the non-destructive testing of the coating becomes more and more important with the gradual progress in the research on the physical properties of materials.
The non-destructive testing methods for coating mainly include: wedge cutting method, optical section method, electrolysis method, thickness difference measurement method, weighing method, X-ray fluorescence method, β-ray reflection method, capacitance method, magnetic measurement method and eddy current measurement law etc. Except for the last five methods, most of these methods will damage the product or the surface of the product. They are destructive testing, and the measurement methods are cumbersome and slow, and they are mostly suitable for sampling inspection.
X-ray and β-ray reflectometry can be used for non-contact and non-destructive measurement, but the device is complicated and expensive, and the measurement range is small. Because of the radioactive source, the user must abide by the radiation protection regulations, and it is generally used to measure the thickness of each layer of metal coating.
The capacitance method is generally only applied to the thickness test of the insulating coating of very thin conductors.
Magnetic measurement method and eddy current measurement method, with the increasing progress of technology, especially after the introduction of microprocessor technology in recent years, the thickness gauge has taken a big step towards miniature, intelligent, multi-functional, high-precision and practical aspects. The measurement resolution has reached 0.1μm, and the accuracy can reach 1%. It also has the characteristics of wide application range, wide measuring range, easy operation and low price. It is the most widely used instrument in industry and scientific research. Ultrasonic level gauge, ultrasonic liquid level gauge, ultrasonic thickness gauge.
The non-destructive testing method is used to measure the thickness without damaging the coating or the substrate, and the testing speed is fast, so a large amount of testing work can be carried out economically.
