Spectral emission of radiation by glass

The spectral radiation emitted normally from the surface of a thin sheet of glass having a specified temperature distribution throughout its thickness is calculated for the wavelength range 1.0 to 6.0 μ. From the results obtained, the design of a radiation pyrometer capable of measuring both the surface and inside temperatures of the glass is described. The pyrometer consists of two radiation detectors, one with a filter to measure only the radiation arising from, and hence the temperature of, the surface of the glass, the other with a filter to measure the radiation arising from the interior of the glass and which therefore has a response dependent on the temperature distribution within the glass.