Optical-based UV-IR gas detector for monitoring hydrocarbons and toxic gases

The IR and ultraviolet emission spectra of hydrocarbons and toxicants was measured and analyzed as compared to theoretical data at room temperature. Based on this data we constructed an electro-optical gas detector for monitoring low concentrations of flammable paraffins, aromatics, and toxic hydrogen-sulfide. The optical method uses two wavelengths at several spectral bands: the signal and the reference which is sampled at a region where the hazardous gas does not absorb at all. Our apparatus is an innovative system that provides fast and reliable explosion detection at different LEL levels. As well, it can provide identification of low concentration of toxicants in the range of parts per million. The apparatus includes a fire detection option that can offer at the same time an automatic activation of fire suppression or neutralization system. It can detect paraffins in the range between 0.03 to 20 LEL per 1 meter by using the infrared spectral band, and aromatics and hydrogen sulfide in the range between 100 to 2000 ppm per 1 meter by using the ultraviolet spectral band. At both regions the accuracy is about 20%. This open-path, line-of-sight gas detector can monitor and transmit an alarm signal prior to occurrence of fire or explosion.