§ 75.22 Reference test methods.
(a) The owner or operator shall use the following methods, which are found in appendices A-1 through A-4 to part 60 of this chapter, to conduct the following tests: Monitoring system tests for certification or recertification of continuous emission monitoring Systems; NOX emission tests of low mass emission units under § 75.19(c)(1)(iv); NOX emission tests of excepted monitoring systems under appendix E to this part; and required quality assurance and quality control tests:
(1) Methods 1 or 1A are the reference methods for selection of sampling site and sample traverses.
(2) Method 2 or its allowable alternatives, as provided in appendix A to part 60 of this chapter, except for Methods 2B and 2E, are the reference methods for determination of volumetric flow.
(3) Methods 3, 3A, or 3B are the reference methods for the determination of the dry molecular weight O2 and CO2 concentrations in the emissions.
(4) Method 4 (either the standard procedure described in section 8.1 of the method or the moisture approximation procedure described in section 8.2 of the method) shall be used to correct pollutant concentrations from a dry basis to a wet basis (or from a wet basis to a dry basis) and shall be used when relative accuracy test audits of continuous moisture monitoring systems are conducted. For the purpose of determining the stack gas molecular weight, however, the alternative wet bulb-dry bulb technique for approximating the stack gas moisture content described in section 2.2 of Method 4 may be used in lieu of the procedures in sections 8.1 and 8.2 of the method.