MEASURING DEVICE OF DISTRIBUTION OF THICKNESS OF OXIDE FILM

• Main Authors: TANAKA TOMIO, HIRANO SHINYA, TANAKA KEIHACHIRO
• Format: Patent
• Language: English
• Published: 17.01.1992
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

PURPOSE:To automate measurement and to improve the precision in measurement by setting a plane-shaped heat radiation source above a metal plate to be measured and by determining the thickness of an oxide film on the basis of reflectance calculated from irradiation luminance and reflection luminance, in measurement of the distribution of the thickness of the oxide film of a steel plate strip or the like. CONSTITUTION:In a process of forming an oxide film on the upper surface of a metal plate 5 which is an object of measurement, a plane-shaped heat radiation source 1 is set above the metal plate 5. The distribution of reflection luminance in a reflection image part 4 on the metal plate 5 is measured by a detector 2 using a two-dimensional array element. An arithmetic device 3 calculates reflectance rholambda from irradiation luminance determined from a reflection luminance signal Llambda and a signal of a surface temperature of the heat radiation source 1, by rholambda = Llambda/Llambda0. Moreover, it determines the thickness (d) of the oxide film from an equation d = F(rholambda) which is stored beforehand. A detection wavelength lambda is set to be larger than 4.n.dmax and the reflectance and the thickness of the oxide film are made to correspond to each other, 1 to 1.