https://www.mikrometry.com/products/etg15fn-eddy-current-digital-coating-thickness-gau.html 1. The strong magnetic field interferes with the measurement results of the coating thickness meter Experiments have proved that when the coating thickness gauge is working near an electromagnetic field of about 10,000V, the measurement will be severely disturbed. If it is very close to the electromagnetic field, it may crash.All Rights Reserved