Transfer Standards for the Calibration of Ambient Air Monitoring Analyzers for Ozone, Technical Assistance Document

摘要

This document is intended as a reference aid to help users select ozone transfer standards and reference them to a higher level UV standard. It first describes the theory of traceability, defines ozone transfer standards and then discusses their purpose and role in calibrating ambient ozone analyzers. The various advantages and disadvantages of ozone transfer standards are pointed out to help users determine whether to use a transfer standard or the UV procedure directly. Different types of ozone transfer standards are described, including analytical instruments and ozone generation devices. The major part of the document is devoted to the procedures necessary to establish the authority of ozone transfer standards: qualification, verification, and periodic reverification. Qualification consists of demonstrating that a candidate transfer standard is sufficiently stable (repeatable) to be useful as a transfer standard. Repeatability is necessary over a range of variables such as temperature, line voltage, barometric pressure, elapsed time, operator adjustments, or other conditions, any of which may be encountered during use of the transfer standard. Tests and possible compensation techniques for several such common variables are provided. Detailed verification procedures are also provided together with the quantitative verification acceptance criteria. Finally, the periodic procedure and specifications necessary to maintain continuous verification of the transfer standard are given.