Study of the Radiation Emitted During the Combustion of Pyrotechnic Charges. Part I: Non Stationary Measurement of the Temperature by Means of a Two-Color Pyrometer

Abstract

Ignition and combustion of pyrotechnic mixtures in a closed volume were carried out by squib type devices. Measurements and numerical simulations in a previous study showed that the phenomenon is very fast with durations of about 200 μs. The objective of this work is to present temperature measurements obtained by means of a two-color pyrometer. A specific pyrometric device was built to carry out these measurements, analyzing the radiation emitted by the pyrotechnic flame. It was concluded that the phenomenon is primarily controlled by the emission of particles. The radiation peculiar to the gases, inside the flame, is negligible. From these assumptions, a method can be established enabling to process the voltage signals from the pyrometer. The measuring apparatus was validated for very short response times in the order of μs. The temperature measured this way seems to reach a constant level for the first 50 μs of combustion. The luminance signals then continue to increase and a decrease in the temperature which reaches approx. 3000 K is observed.