Opsis open-path monitor versus conventional point samplers in a field study

摘要

Abstract: During late summer of 1993 a field study took place in Baytown, Texas, where a comparison was made between the Opsis open-path system and conventional point sampling monitors. Simultaneous measurements of the three criteria pollutants sulfur dioxide, nitrogen dioxide, and ozone were made during a time period of a month, including data on wind speed, wind direction, and temperature. This study was made in an area with numerous major local sources of pollution. The degree of agreement between the open-path system and the point measurement system depended on the gas being measured. Ozone, which is well mixed, showed very good intercomparison whereas SO$-2$/ showed poor intercomparison from time to time. By studying the discrepancies as function of the wind direction, interesting results were obtained. !9