Pyrometry using photothermal effect

International audienceThe radiation leaving a solid surface results from both emission and reflection. Only the first contribution depends on the temperature. An important and still unsolved problem in pyrometry is to measure the emission separately and quantitatively. We propose a new temperature measurement technique based on the photothermal effect for which the emission is modulated ;the emission (intrinsic radiation)is then isolated from extraneous radiations by using a suitable detection system. Temperature measurements are presented, made on a steel sample placed inside a furnace. They show a relative accuracy better than 2% .Finally we present an improvement of the method which could eliminate the unknown emissivity