Temperature measurements in hot glass melts

For efficient production of glass (minimization of energy usage) and glass products (minimization of material usage), it is important to monitor the temperature distribution during the production and forming processes. The most common methods for temperature determination are probes (thermocouples) and single-wavelength pyrometers. These methods show many limitations. For thermocouple measurements the probe is in contact with the glass. With pyrometer measurements it is only possible to determine surface temperatures. In the study a new temperature measurement method is presented, which is based on intensity measurements at various wavelengths in the infrared spectrum. Advantages of this method are that there is no contact with the glass and that temperature profiles in the glass are measured rather than surface temperatures. Possible practical applications of this method are the determination of temperature profiles in feeders and gobs. Within this new temperature measurement method a model is developed which describes the spectral intensity emerging from the glass as function of the temperature distribution in the glass. Next, the calculated spectral intensity is confronted with the measured spectral intensity to reconstruct the temperature distribution