Application: magnetic sensors are used to measure non-magnetic 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. Eddy current sensor is used to measure enamel, rubber, paint and plastic layers on copper, aluminum, zinc, tin and other substrates.