- P-ISSN 1225-0163
- E-ISSN 2288-8985
A detector for monitoring carbon monoxide (CO) in ambient air by nondispersive infrared (NDIR) spectroscopy has been developed and investigated its sensitivity and stability. The essential parts of the absorption cell are three spherical concave mirrors so as to improve the sensitivity by increasing the light path length in the cell. The radius and center of curvature of mirrors and position in the cell was calculated by computer simulation in order that the light path length may be 16m into the 50cm cell. The number of traversals and optical path properties were confirmed by laser beam alignment in transparent absorption cell. The photoconductive type lead selenide (PbSe) was used as CO sensing material, which was cooled to increase the responsibility by thermoelectric cooling method. The detection limit and span drift of the developed CO detector was 0.24ppm and 0.03ppm(v/v) respectively.