REMOTE THREE-WAVE METHOD OF MEASURING THICKNESS OF FILM FILMS Russian patent published in 2007 - IPC G01B11/06 G01N21/17 

FIELD: measuring technique.

SUBSTANCE: method can be used for measuring and inspecting thickness of film films of oil products in sewage works, in internal pools, water areas of ports. Remote three-wave method of measuring thickness of film films onto surface of matter is based upon irradiation of surface by optical radiation at three wavelengths of probing λ₁,λ₂ and λ₃ correspondingly, upon registration of signal reflected from surface and upon measurement of thickness d of film from results of analysis of intensity of reflected signal relating to wavelength. Mentioned wavelengths λ₁, λ₂ and λ₃ are chosen in such a way that λ₁=λ₂-Δλ and λ₃=λ₂+Δλ. Moreover Δλ is chosen to correspond to inequality of 4πdn₂ (λ₂) Δλ/ λ₂ ²≤π/2, where n₂ is refractivity factor of thin film.

EFFECT: reduced number of probing waves; widened range of measured thicknesses.

2 dwg