The working principle of coating thickness gauge mainly includes magnetic attraction measurement principle and magnetic induction measurement principle.
Magnetic attraction measurement principle: This principle uses the fact that the attraction between permanent magnet (probe) and magnetic steel is proportional to the distance between them. When the magnetic steel is attracted to the object to be measured, the measuring spring gradually stretches and the pulling force gradually increases. When the pulling force is just greater than the attraction force, the magnitude of the pulling force is recorded at the moment when the magnetic steel is separated to obtain the coating thickness.
Magnetic induction measurement principle: This method uses the magnitude of the magnetic flux from the probe through the non-ferromagnetic coating and into the ferromagnetic substrate to determine the coating thickness. The thicker the coating, the greater the magnetic resistance and the smaller the magnetic flux. The thickness gauge using this principle can measure the thickness of the non-magnetic coating on the magnetic substrate.
Application field: Coating thickness gauges are widely used in manufacturing, metal processing, chemical industry, commodity inspection and other fields to measure the thickness of non-magnetic coatings on magnetic metal substrates, such as aluminum, chromium, copper, enamel, rubber, paint, etc. In addition, it can also measure the thickness of non-conductive coatings on non-magnetic metal substrates, such as enamel, rubber, plastic, etc.
Technological Development: Modern coating thickness gauges have introduced new technologies such as frequency stabilization, phase locking, and temperature compensation, and use patented integrated circuits and microcomputers to significantly improve measurement accuracy and reproducibility. The resolution can reach 0.1um, the allowable error is 1%, and the range is 10mm.