Download the Code of Federal Regulations in XML.
The Electronic Code of Federal Regulations (e-CFR) is a regularly updated, unofficial editorial compilation of CFR material and Federal Register amendments produced by the National Archives and Records Administration's Office of the Federal Register (OFR) and the Government Publishing Office.
Parallel Table of Authorities and Rules for the Code of Federal Regulations and the United States Code
Text | PDF
Find, review, and submit comments on Federal rules that are open for comment and published in the Federal Register using Regulations.gov.
Purchase individual CFR titles from the U.S. Government Online Bookstore.
Find issues of the CFR (including issues prior to 1996) at a local Federal depository library.
Electronic Code of Federal Regulations
Title 40: Protection of Environment
§90.323 Analyzer bench checks.
(a) Prior to initial use and after major repairs, verify that each analyzer complies with the specifications given in Table 2 in Appendix A of this subpart.
(b) If a stainless steel NO2 to NO converter is used, condition all new or replacement converters. The conditioning consists of either purging the converter with air for a minimum of four hours or until the converter efficiency is greater than 90 percent. The converter must be at operational temperature while purging. Do not use this procedure prior to checking converter efficiency on in-use converters.