| The development of a multiple detection site gas detector was undertaken. Using absorption detection via Tunable Diode Laser Spectroscopy [TDLS], a fiber optic light distribution system was assembled to supply several remote detection heads with atmospheric probing laser light. The system can be used for a wide variety of molecular species exhibiting absorption at wavelengths between 1.3 mum to 1.7 mum. The toxic gas Hydrogen Sulfide, H2S, was chosen as the detection gas for this project because of potential uses in the petrochemical industry. Development and testing of a signal subtraction routine was undertaken in order to compensate for the presence of a stable absorption background. A sensitivity of ∼10 PPMM is reached for the test H2S absorption line. |
