Non-contact wet or dry film thickness measuring device

摘要

A device for measuring the thickness of a wet or dry paint film applied on a substrate without contacting the film is disclosed. The device uses an optical sensor positioned centrally and coaxially with an inductive eddy-current proximity sensor. The optical sensor measures the distance between the device and the upper surface of the paint film at specular reflection angle. The proximity sensor measures the distance between the device and the upper surface of the substrate. The two distances measured, when compared, produce the film thickness value. The device is capable of accurately measuring thickness of various paint films, such as flat, glossy and metal-flake containing paint films.