Gallium Arsenide Semiconductor-Laser Multigas Analyzer (GASMAN).

摘要

The U. S. Army requires an instrument for monitoring gaseous by- products, including HCL, NO2, CO2, CO, etc. generated by newly developed gunpowder and combustion fuels, and in evaluating their threats to the health of soldiers. It is desired to perform simultaneous real time monitoring of these gas concentrations in ambient air with detection sensitivities at or below the Threshold Limit Value (TLV) levels. This Phase II SBIR final report discusses the features and capabilities of the Spectral Sciences, Inc. (SSI) Gallium Arsenide Semiconductor-laser Multigas Analyzer (GASMAN) for detecting multiple toxic gases using optical absorption. GAS MAN utilizes commercial indium gallium arsenide phosphate (InGaAsP) diode lasers developed for communications and digital storage and readout. The high reliability and stability of these lasers make them well-suited for instruments requiring long-term unattended operation. Line-locking and laser wavelength modulation techniques implemented in SSI's field instrument designs insure selective, sensitive detection of the desired species on a time scale of 80 ms.