Measurement of NO, NO/sub 2, and HNO/sub 3 using a tunable diode laser system. Phase 2: Modification to permit automated simultaneous multi-species monitoring and feasibility study of extension to H/sub 2O/sub 2, CH/sub 2O and HONO

The tropospheric air monitoring system (TAMS) was modified to permit nearly simultaneous monitoring of two or more species. The system was developed to allow for computer control of the laser systems and computer data acquisition which could provide real time data analysis. The system can monitor at least two of NO, NO2, and HNO3 nearly simultaneously (within five seconds) in the troposphere at sub-part-per-billion-by-volume (ppbv) levels. A second task was to perform studies on additional species to determine the feasibility of using the TAMS in their detection. This was done for three species: H2O2, CH2O, and HONO. Lasers were obtained for all three species, and regions in their absorption spectrums free from interferences due to other tropospheric constituents were identified. Detection limits of less than a few ppbv were determined for H2O2 and CH2O and were measured in doped by synthetic air and in ambient laboratory air.