THE MEASUREMENT OF EXTINCTION OF INFRARED SCREENING SMOKE

摘要

The extinction coefficient is one of the most important performance parameters that are used to judge screening smoke performance of a material. It follows Beer's law. The experimental equipment is composed of a smoke chamber, a radiometer and a blackbody used as the radiated source. After introducing smoke into the chamber, the radiance of blackbody with smoke and the radiance of blackbody without smoke are alternatively measured by the radiometer. The spectral transmission can be calculated with the measured blackbody's radiance. The radiation of background and smoke and the throughput loss are considered in the experiment. Glass fiber filter, a rotometer and vacuum pump are used to make mass concentration measurement. Spectral transmission and concentration are measured and then according to Beer's law the spectral mass extinction coefficient can be calculated with the optical length known. Spectral transmission, average transmission and extinction coefficient is provided.