| 摘要 |
PURPOSE:To measure the thickness of films with simple constitution by a method suited for on-line measurement by irradiating light of a wavelength region of large absorption and light of a wavelength region of small absorption to the film to be measured and detecting the ratio of the intensities of reflection thereof. CONSTITUTION:Beams of a visible ray (wavelength lambda2) and a UV ray (wavelength lambda1) from light sources 2 and 3 are irradiated via collimators 4, 5, half mirrors 6-8, and a mirror 18 to a material 1 to be measured such as a plated steel plate deposited with a hydrated chromium oxide. The reflected beams from the mirrors 6, 7 are measured via filters 14. 15 with detectors 10, 11 and the reflected beams of the material 1 are measured via filter 16, 17 with detectors 12, 13. From the ratio I(lambda1)/I(lambda2) of both measured values and the known coefft. of absorption of the film, the thickness of the film is calculated with an arithmetic device 20, and is displayed 21. Thereby, the thickness of the film is measured by the method suited for on-line measurement with the simple constitution. |
