Development of Radiation Pyrometer for Time-Resolved Measurement of Temperatures in Shock-Wave Compression Experiments

摘要

We have developed a radiation pyrometer system for time resolved measurement of temperature in materials subjected to shock loading or to sudden deposition of energy by any other means. This instrument has four channels, with each channel equipped with interference filter and photo-receiver. The interference filter selects the desired wavelength in the visible to near infrared range and the photo-receiver converts the filtered radiation into an electrical signal. The FWHM bandwidth of the interference filter is -10 nm around the selected central wavelength and the dynamic bandwidth of proto-receiver is -125 MHz which corresponds to time resolution of ~3ns. The output of photo-receivers at each channel is recorded in fast Digital Storage Oscilloscope (DSO). The recorded intensities at a given instant of time for four wavelength are fitted to Plank's radiation law and the information about the temperature and emissivity of the object is obtained. A software code has been developed to analyze the experimental data for generating time resolved profile of temperature and emissivity. The instrument is demonstrated to make steady state temperature measurement of standard Tungsten Halogen Lamp Source (THLS) with an accuracy of -5%. Also it has been used for the measurement of time resolved temperature profile of electrically exploded conducting wire (copper) having transient of the order of-15 ns.