Accuracy Assessment of EPA Protocol Gases in 1988

Abstract

The US Environmental Protection Agency has established quality assurance procedures for air pollution measurement systems. These procedures are intended to reduce the uncertainty of environmental measurements. Among the areas of EPA's concern is the accuracy of compressed gas standards and liquid permeation standards used for calibration and audits of continuous emission monitoring systems and ambient air quality analyzers. EPA's regulations specify that the certified values for these standards be traceable to National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs) or to NIST/EPA-approved Certified Reference Materials via two traceability protocols. These protocols were published originally in 1978 and were revised in 1987. Following publication of the revised traceability protocols, EPA conducted an accuracy assessment of compressed gas standards in 1988. These standards were to be prepared and analyzed by specialty gas producers according to the revised protocols. EPA directed Research Triangle Institute to purchase from all available sources and to analyze the following gas mixtures: 300 ppm SO{sub 2} in N{sub 2}; 400 ppm NO in N{sub 2}; and 30 ppm CO in air.