Basic working principle of eddy current coating thickness gauge
The basic working principle of eddy current coating thickness gauge. Modern engineering material development and application practice have shown that various non-ferrous metal materials such as aluminum, copper, zinc, and their alloy materials are widely used in industries such as aviation, building materials, metallurgy, light industry, machinery, instruments, and chemical engineering. Often, anti-corrosion protection of surface coatings such as oxide film, paint, spray coating, and rubber is needed to extend their service life. The eddy current coating thickness gauge developed using eddy current technology is an effective means of non-destructive measurement of the thickness of non-conductive coatings on non-magnetic metal substrates listed above.
The basic working principle of eddy current coating thickness gauge is that when the measuring head comes into contact with the tested sample, the high-frequency electromagnetic field generated by the measuring head device causes the metal conductor placed below the measuring head to generate eddy currents. The amplitude and phase of the eddy currents are functions of the non-conductive coating thickness between the conductor and the measuring head. That is, the alternating electromagnetic field generated by the eddy currents will change the parameters of the measuring head, and the size of the measuring head parameter variable depends on the thickness of the coating layer. By measuring the size of the measurement head parameter variable and converting this electrical signal, the thickness value of the measured coating layer can be obtained.
The detection principle of eddy current coating thickness gauge
A coating thickness gauge is a professional measuring instrument for detecting the thickness of coatings or coatings, so it can also be called a coating thickness gauge. The coating thickness gauge produced by Jining Aotai is a professional measuring instrument for detecting the thickness of coatings or coatings on metal surfaces. Specifically, it can be divided into magnetic thickness gauges for detecting the thickness of coatings on magnetic metal surfaces (such as zinc, copper, chromium coatings or coatings on steel surfaces, enamel, fiberglass, spray coating, asphalt, etc.), and thickness gauges for coating on non-magnetic metals (such as paint on non-ferrous metals, paint on aluminum substrates, or oxide films, etc.). These types of thickness gauges for detecting the thickness of non-magnetic metal coatings are commonly referred to as thickness gauges. Eddy current thickness gauge, which uses eddy current thickness measurement method for thickness detection. Today, we will talk about the principle of eddy current thickness gauge.
The main difference between eddy current thickness gauge and magnetic induction principle is the measurement probe, while non-magnetic probes use high-frequency materials as the coil core. When high-frequency AC signals generate an electromagnetic field in the probe coil, eddy currents are formed in it when the probe is close to the conductor. The closer the probe is to the conductive substrate, the greater the eddy current and reflection impedance. This feedback action characterizes the distance between the probe and the conductive substrate, which is the thickness of the non-conductive coating on the conductive substrate. Due to the fact that this type of coating thickness gauge probe is specifically designed to measure the coating thickness on non-ferromagnetic metal substrates, it is commonly referred to as a non-magnetic probe. Eddy current thickness gauge, in principle, can measure non-conductive coatings on all conductive substrates, such as paint, plastic coatings, and anodized films on surfaces of aerospace aircraft, vehicles, household appliances, aluminum alloy doors and windows, and other aluminum products.
