Patent ID: 7414740
Filing Date: 2008-08-19
Classification: G01B

Abstract:
1. A method of measuring a thickness of a glass body without direct contact with the glass body by means of optical dispersion immediately after production of the glass body, said method comprising the steps of: a) focusing a light beam from a polychromatic light source on the glass body by means of a focusing device immediately after forming the glass body; b) when the light beam is focused on the glass body, conducting reflected light from the glass body into a spectrometer in order to obtain a spectrum of the reflected light; c) finding two wavelengths of the reflected light from the front side and the rear side of the glass body respectively in the spectrum obtained in step b) at which reflected light intensities are greater than remaining wavelengths of the spectrum; d) determining the thickness of the glass body from a wavelength difference of said two wavelengths of higher intensity, considering a refractive index of the glass body; e) maintaining the focusing device at a temperature below 120° C. during the measuring of the thickness; and f) substantially preventing heat radiation from acting on the focusing device by means of at least one heat-blocking filter.