DEVICE FOR MEASURING COATING THICKNESS

The invention relates to a device for measuring a thickness of a dielectric layer (8) on a base substrate (7), comprising a cylindrical resonant cavity (1) having a circular cylindrical wall (9) and a plane wall (10) on one end thereof, wherein the opposite end (3) is open to be placed upon the dielectric layer (8) on the substrate (7) to form a wall of the resonant cavity (1) on the opposite end (3); an antenna (4) located within said resonant cavity (1) and adapted to excite an electromagnetic field in the resonant cavity (1) that is approximately zero in the dielectric layer (8); a reflection meter (5) connected to said antenna (4) and adapted to measure the resonant frequency of the resonant cavity (1); and a processor (6) connected to said reflection meter (5) and adapted to determine the thickness of the dielectric layer (8) from the resonant frequency of the resonant cavity (1).