METHOD MEASURING THICKNESS OF SHEET GLASS AND DEVICE FOR ITS REALIZATION Russian patent published in 2000 - IPC

FIELD: measurement technology. SUBSTANCE: invention can be employed for contact-free automatic measurement of thickness of transparent materials, for example, sheet glass in continuous production process. Method measuring thickness of sheet glass consists in direction of two uniaxial converging homocentric light beams formed in the form of conical surfaces with different convergence angles on to glass. Refractive index of glass and its thickness are computed by diameters of light rings in registration plane located in point of convergence of beams. Wedge shape of glass plate is determined by displacement of center of light rings with reference to optical axis and deviation of glass surface from plane is evaluated by local deviations of rings from circumference. Device for realization of method has radiation former so manufactured that it allows radiation to be transformed into two uniaxial converging homocentric light beams and photodetector fabricated in the form of multichannel two-coordinate photographing unit coupled to register. EFFECT: increased measurement precision thanks to simultaneous measurement of refractive index of glass, test of wedge shape of glass and of local deviations of glass surface from plane in addition. 2 cl, 2 dwg