Classification of coating thickness gauges and differences between F, N, and FN
The thickness measured by coating thickness measurement refers to the thickness of the coating layer, which forms a covering layer for surface protection and decoration of materials, such as coatings, coatings, coatings, stickers, chemically generated films, etc., and is referred to as coating in relevant national and international standards.
Measurement of coating thickness has become an important part of quality inspection in the processing industry and surface engineering, and is an essential means for products to meet high-quality standards. In order to internationalize our products, there are clear requirements for the thickness of the coating in our country's exported goods and foreign-related projects.
The main measurement methods for coating thickness include wedge cutting method, light cutting method, electrolysis method, thickness difference measurement method, weighing method, X-ray fluorescence method β X-ray backscatter method, capacitance method, magnetic measurement method, eddy current measurement method, etc. The first five of these methods are lossy detection, with cumbersome and slow measurement methods, and are mostly suitable for sampling inspection.
X-ray and β The X-ray method is a non-contact non-destructive measurement, but the equipment is complex and expensive, and the measurement range is small. Due to the presence of radioactive sources, users must comply with radiation protection regulations. The X-ray method can measure extremely thin coatings, double coatings, and alloy coatings. β The X-ray method is suitable for measuring coatings and substrates with atomic numbers greater than 3. The capacitance method is only used for measuring the thickness of the insulation layer of thin conductive materials.
With the increasing progress of technology, especially in recent years after the introduction of microcomputer technology, thickness gauges using magnetic and eddy current methods have taken a step towards miniaturization, intelligence, multifunctional, high-precision, and practicality. The resolution of the measurement has reached 0.1 micrometers, and the accuracy can reach 1%, which has greatly improved. It has a wide range of applications, a wide range, simple operation, and low cost, making it a widely used thickness measuring instrument in industry and scientific research.
The use of non-destructive methods neither damages the coating nor the substrate, resulting in fast detection speed and the ability to economically carry out a large amount of testing work.
F represents ferrous ferromagnetic matrix, and the F-type coating thickness gauge uses the principle of electromagnetic induction to measure non ferromagnetic coatings and coatings on ferromagnetic metal substrates such as steel and iron, such as paint, powder, plastic, rubber, synthetic materials, phosphating layer, chromium, zinc, lead, aluminum, tin, cadmium, porcelain, enamel, oxide layer, etc.
N represents Non ferrous non ferromagnetic matrix, and the N-type coating thickness gauge adopts the principle of eddy current; To measure enamel, rubber, paint, plastic layers, etc. on substrates such as copper, aluminum, zinc, tin, etc. using eddy current sensors.
The FN type coating thickness gauge adopts both electromagnetic induction principle and eddy current principle, and is a two in one type coating thickness gauge for both F and N types.
Function: Measure the thickness of non conductive coatings on magnetic objects and non conductive coatings on non magnetic metal substrates
Application: Use magnetic sensors to measure non ferromagnetic coatings and coatings on ferromagnetic metal substrates such as steel and iron, such as paint, powder, plastic, rubber, synthetic materials, phosphating layer, chromium, zinc, lead, aluminum, tin, cadmium, porcelain, enamel, oxide layer, etc. Measure enamel, rubber, paint, plastic layers, etc. on substrates such as copper, aluminum, zinc, and tin using eddy current sensors. Widely used in testing fields such as manufacturing, metal processing, chemical industry, and commodity inspection.
