Performance Audits of EPA Protocol Gases and Inspection and Maintenance Calibration Gases

Abstract

Two performances audits of calibration gas mixtures were conducted by RTI in 1985 to assess the accuracy of certified concentrations assigned by speciality gas producers. The first audit involved the purchase and analysis of EPA Protocol No. 1 gases from 11 specialty gas producers. These mixtures contained sulfur dioxide in nitrogen, nitric oxide in nitrogen, and carbon monoxide in air. Such mixtures are used for the calibration and auditing of ambient air quality analyzers and continuous emissions monitoring systems. The second audit involved the purchase and analysis of I/M calibration gases from 13 specialty gas producers. These mixtures contained carbon monoxide and propane in nitrogen. Such mixtures are used for the calibration and auditing of motor vehicle emission analyzers. This note summarizes the analytical results from these two audits.