Analysis of Commercial Cylinder Gases of Nitric Oxide, Sulfur Dioxide, and Carbon Monoxide at Source Concentrations: Results of Audit 5

摘要

Manufacturers of commercial cylinder gases supply standards with a certified analysis and a statement of accuracy. Generally, the level of accuracy is specified as a percentage of the component value. To ascertain the accuracy of analyses of commercially available cylinder gases, the Environmental Protection Agency (EPA) has initiated a national performance audit program of commercial gas manufacturers. Audit 1 was performed in June 1978, Audit 2 was performed in January 1979, Audit 3 was performed in September 1979, and Audit 4 was performed in April 1980. A summary of these results is included in this report. The purpose of Audit 5 was to analyze the concentration of cylinder gases purchased from a representative sample of manufacturers and determine the accuracy of the manufacturers' certified concentrations. Audit 5 included cylinders of sulfur dioxide (SO2) at 90 and 500 ppm, nitric oxide (NO) at 50 and 300 ppm, and carbon monoxide (CO) at 50 and 500 ppm obtained from 14 different manufacturers. Audit 5 was performed from March through June 1981. Audit 5 results are summarized in this report.