Spectrophone Measurements of Air Pollutants Absorption Coefficients at CO2Laser Wavelengths

Laser optoacoustic spectroscopy technique has been employed to measure the absorption coefficients of seven gas pollutants at CO2 laser wavelengths between 9.2 μm and 10.8 μ. All measurements were performed with the pollutant at a low pressure in the presence of 1 atm of nitrogen. Out of these seven gases sub-ppm quantities of ethylene, ammonia, freon 12, thrichlorethylene, ethanol and toluene can be detected with the same apparatus.