An inverse method for determining transient temperature distribution in glass plates

Abstract

Experimental measurements of the transient internal temperature distributions in 2.26, 3.71 and 6.76 mm thick glass plates using thermocouples fused in the glass and by the spectral remote sensing (SRS) method have been carried out. Experimentally measured and reconstructed temperatures are compared to predictons based on the solution of the transient energy equation where the internal radiative transfer has been accounted for using rigorous radiative transfer theory. A discussion of the experimental method to determine the temperatures, and the validation of the energy model and of the SRS method is included. The measurements were made as the test plates cooled, from an initial temperature of approximately 520 °C, by radiation and natural convection in the laboratory ambient. Temperatures determined by the SRS method are compared with those from thermocouples fused in the glass and with theoretical predictions to demonstrate the accuracy and limitations of the SRS method. The agreement between the SRS method, thermocouple measurements, and theoretical predictions show that the SRS method can be used to determine the front, center and back temperatures to within approximately ± 0.5%, ± 1.0% and ± 5.0%, respectively, for a 3.71 mm thick glass plate when intensity of radiation emerging from the plate is measured from one side.