Evaluation and Use of Stand-Alone Commercial Photolytic Converters for Conversion of NO(sub 2) to NO

摘要

Two types of stand-alone photolytic converters of nitrogen dioxide (NO2) to nitric oxide (NO) are now commercially available for use with NO, ozone (O3) chemiluminescence's detector (CLD) monitors for the measurements of NO2. Both units have been tested for interferences resulting from photolysis of nitrous acid (HONO) and from the decomposition of peroxyl acetyl nitrate (PAN). One unit is based on the use of a broadband source and the other on a light-emitting diode (LED) array with output emission wavelengths centered near 390 nm. Evaluation results indicate that the use of either converter with an external, heated metal (molybdenum) converter and a chemiluminescence's monitor to measure NO, NO2, and NOY seems reasonable.