Patent ID: 6074087
Filing Date: 2000-06-13
Classification: G01J

Abstract:
A non-contact method for measuring a surface temperature distribution of a melt during growth of ionic crystals, in which an ionic crystal comprises a long-wavelength absorption edge and a Reststrahlen band having high reflectance, and wherein the crystal has an opaque spectral region having low reflectance and high absorption in a range between the long-wavelength absorption edge and the onset of the Reststrahlen band; the non-contact method for measuring surface temperature of ionic crystals comprising:a. melting the ionic crystal to form a solid coexistent with said melt;b. receiving a thermal radiation intensity distribution emitted from a surface of the ionic crystal to be measured, said received radiation being within said opaque spectral region;c. obtaining a surface thermal radiation intensity within said opaque region at a solid-melt-gas interface of the ionic crystal at a predetermined temperature of a melting point thereof and dividing said obtained intensity by a blackbody radiation intensity at a same temperature to obtain an emissivity at the melting point; andd. converting the received surface thermal radiation intensity to a surface temperature distribution of the ionic crystal from the derived emissivity.