The most appropriate monitoring methods for reactive nitrogen oxides are identified subject to the requirements for diagnostic testing of air quality simulation models. Measurements must be made over one hour or less and with an uncertainty of equal to or less than 20% (10% for NO2) over a typical ambient concentration range extending from a lower limit of 1ppbv. NO, NO2, HNO3, PAN, and other reactive nitrogen oxides that exist at the 1ppbv level and above, along with the compound sets designated as NO y, NO x, and the difference, NO z are included in this measurement requirement. New and/or improved measurement techniques for NO2 monitoring including laser-induced fluorescence, photolytic conversion/NO,O3 chemiluminescence, differential optical absorption spectroscopy, and NO2/luminol chemiluminescence are examined with reference to literature citations and to field monitoring as part of the 1999 SOS Summer Field Study in Nashville, TN. Existing approaches to monitoring the other most prevalent reactive oxides of nitrogen are reviewed. At the lower end of the ambient monitoring range, research-grade instruments are often needed and operator skill, experience, and close attention are critical to proper instrument operation, calibration, and maintenance.

"EPA-600/R-01/005." "September 2000." Microfiche.