Abstract

To meet an important need in air pollution science, an atmospheric gas monitor that simultaneously achieves sensitive real-time noncontacting and local measurement with portable equipment has been developed. A schematic diagram of the system developed is shown in Fig. 1. The PbSnTe diode laser provides 0.1 mW at 7.6-μm emission and is cooled by liquid nitrogen. The laser beam runs through the atmosphere over a path length L_x (≑1 m) and is then divided into two. One beam impinges onto a HgCdTe IR detector, and the other beam passes through a gas ceil of length L_r and concentration c_r before reaching the other detector.

© 1983 Optical Society of America