Film thickness gauge
Also known as coating thickness gauge, it can measure the thickness of non-magnetic coating (such as aluminum, chromium, copper, enamel, rubber, paint, etc.) on magnetic metal substrate (such as steel, iron, alloy, hard magnetic steel, etc.) and the thickness of non conductive coating (such as enamel, rubber, paint, plastic, etc.) on non-magnetic metal substrate (such as copper, aluminum, zinc, tin, etc.).
Coating thickness gauge has the characteristics of small measurement error, high reliability, good stability and easy operation. It is an indispensable testing instrument to control and ensure product quality. It is widely used in manufacturing, metal processing, chemical industry, commodity inspection and other testing fields.
The coating formed for the surface protection and decoration of materials, such as coating, coating, coating, sticking layer, chemically formed film, etc., is called coating in relevant national and international standards.
Coating thickness measurement has become an important part of quality inspection in processing industry and surface engineering, and is a necessary means for products to reach superior quality standards. In order to internationalize our products, there are clear requirements for the thickness of cladding in our export commodities and foreign projects.
The measurement methods of coating thickness mainly include: wedge cutting method, light cutting method, electrolysis method, thickness difference measurement method, weighing method, X-ray fluorescence method, β X-ray backscattering method, capacitance method, magnetic measurement method and eddy current measurement method, etc. Among these methods, the first five are lossy detection, the measurement means are cumbersome and slow, and most of them are suitable for sampling inspection.
X-rays and β X-ray method is non-contact and non-destructive measurement, but the device is complex and expensive, and the measurement range is small. Due to radioactive sources, users must comply with radiation protection regulations. X-ray method can be used to measure very thin coating, double coating and alloy coating. β X-ray method is suitable for coating and substrate with atomic number greater than 3. The capacitance method is only used to measure the thickness of insulation coating of thin conductor.
With the increasing progress of technology, especially after the introduction of microcomputer technology in recent years, the thickness measuring instrument using magnetic method and eddy current method has taken a step in the direction of miniaturization, intelligence, multi-function, high precision and practicality. The resolution of the measurement has reached 0.1 μ m, and the accuracy can reach 1%. It is the most widely used thickness measuring instrument in industry and scientific research.
The non-destructive method does not damage the coating or the base material, so the detection speed is fast, and a lot of detection work can be carried out economically.