Current Status of EPA Protocol Gas Verification Program

摘要

Accurate compressed gas reference standards are needed to calibrate and audit continuous emission monitors (CEMs) and ambient air quality monitors that are being used for regulatory purposes. US Environmental Protection Agency (EPA) established its traceability protocol to ensure that commercially-produced standards are traceable to the National Institute of Standards and Technology (NIST). The protocol is an analytical procedure that specialty gas producers use to assay the standards with NIST-certified reference standards and to estimate the uncertainty of the certified concentrations. EPA does not have direct oversight of their production of the standards. In 2010, EPA implemented a Protocol Gas Verification Program (PGVP) to verify the accuracy of a random sample of the standards and to disseminate the results of the verifications to end users of the standards. The verifications are performed by laboratories at NIST and EPA Regions 2 and 7. This paper summarizes the results of the verifications to date. The results provide assurance to end users and producers that EPA Protocol Gases are meeting the accuracy requirements of EPA's Acid Rain and Ambient Air (AA) programs.