| Popis: |
Absorption coefficient data are reported for acrolein, styrene, ethyl acrylate, trichloroethylene, vinyl bromide, and vinylidene chloride at up to seventy-two CO2 laser wavelengths each. These compounds are toxic industrial substances for which improved ambient air detection methods are desired. Absorption data for these compounds are needed to determine their detectabilities by CO2 laser-based photoacoustic, long-path absorption, and laser radar (lidar) techniques. The absorption data obtained for these compounds indicate that sub parts-per-billion (ppb) level, interference-free detection limits should be possible for these compounds by the CO2 laser photoacoustic technique. CO2 laser photoacoustic detectabilities of 40 ppb or less should be possible for these compounds in the presence of expected ambient air concentrations of water vapor and other anticipated interferences. In addition, absorption data on the first four compounds are needed to assess the capability of using CO2 laser spectroscopic techniques to detect low levels of the toxic hydrazine-based rocket fuels in air samples containing these compounds as interferences. The absorption data obtained for these four compounds indicate that the hydrazine-fuels should be detectable by the CO2 laser photoacoustic technique at concentrations below proposed workplace standards for hydrazines as low as 30 ppb in the presence of expected airborne concentrations of these compounds together with other expected interferences. |
