Stability Evaluation of Sulfur Dioxide, Nitric Oxide and Carbon Monoxide Gases in Cylinders

摘要

The US EPA recommends in their EPA Traceability Protocol 1 and 2 that reactive gases be reanalyzed every six months. The purpose of this study was to assess the stability of selected reactive gases as a function of time to determine the feasibility of extending the recertification period. The reactive gases in this study were contained in aluminum and steel cylinders and included: carbon monoxide in air (CO/Air); carbon monoxide in nitrogen (CO/N2); nitric oxide in nitrogen (NO/N2); and sulfur dioxide in nitrogen (SO2/N2).