Introduction to the Principle of Metal Substrate Coating Thickness Gauge
Metal substrate coating thickness gauge principle
Coating thickness gauge is also called coating thickness gauge, paint film thickness gauge, coating thickness gauge, film thickness gauge, paint thickness gauge, cladding thickness gauge, electroplating layer thickness gauge, etc.
There are two principles of coating thickness gauges for measuring coatings on metals:
1. Magnetic induction thickness measurement method, which can non-destructively measure the thickness of the non-magnetic coating on the magnetic metal substrate (such as zinc, aluminum, chromium, copper, rubber, paint and other coatings on steel, iron, alloy and magnetic steel).
The working principle of the magnetic induction thickness measurement method: when the measuring head is in contact with the covering layer, the Oupu measuring head and the magnetic metal substrate form a closed magnetic circuit. Due to the existence of the non-magnetic covering layer, the reluctance of the magnetic circuit changes. By measuring the change The thickness of the covering layer can be exported.
2. Eddy current thickness measurement method, which can non-destructively detect the thickness of the non-conductive layer on the non-magnetic metal substrate (such as the paint, rubber, plastic, oxide film and other coating thickness on copper, aluminum, zinc, tin and other metals)
The working principle of the eddy current thickness measurement method is that when the probe is in contact with the sample to be measured, the high-frequency electromagnetic field generated by the probe device causes the metal conductor placed under the probe to generate eddy currents, and its amplitude and phase are between the conductor and the probe. It is a function of the thickness of the non-conductive coating between them. That is, the alternating electromagnetic field generated by the eddy current will change the probe parameters, and the size of the probe parameter variables, and convert this electrical signal to obtain the thickness of the measured coating .
The principle of coating thickness gauges for measuring glass, ceramics, plastics, wood, and concrete surface coatings is ultrasonic, which is called ultrasonic coating thickness gauges.
