Electrically-conductive-film thickness contactless measuring system - has inductive sensors located on opposite sides of substrate for generating sequential mutually attracting and repelling AC magnetic fields, to create eddy currents effects in film for comparison

摘要

The measurement film is arranged at a fixed distance from a sensor which generates a field which causes a physical effect in the measurement field. The sensor can generate different fields in sequence. The physical effects caused by first and second fields are evaluated to determine the film thickness. The field can be a magnetic field and the measurement film is electrically conductive. The film can be placed between a pair of opposing sensors which produce identical fields at one time and different ones at another. The physical effects in the film at the two times are compared. USE/ADVANTAGE - For measuring thicknesses of coatings on bands, foils or plates. Enables problem-free null measurement and calibration.