Nitric oxide oxidation method for field calibration of nitrogen dioxide meters

A simple procedure for field calibration of direct-reading NO2 meters is described. The method involves passing NO at a fixed concentration through an oxidizing reagent. The NO is oxidized to NO2, diluted with zero air and routed into the meter. Problems of working with potentially unstable cylinders of NO2 or field permeation systems are avoided. Both laboratory and field evaluations attest to the suitability of this method. Possible application as a confirmatory laboratory standard is suggested.