40 CFR 90.324 - Analyzer leakage check.
(a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results.
(2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being checked. The analyzer flows and bypass flows may be used to estimate the in-use flow rates.
(3) The sample probe and the connection between the sample probe and valve V2, see Figure 1 in Appendix B of subpart E of this part, may be excluded from the leak check.
(b) Pressure-side leak check. Substantial leaks of the sample on the pressure side of the system may impact sample integrity if the leaks are of sufficient magnitude. As a safety precaution, good engineering practice would require that manufacturers perform periodic pressure-side leak checks of the sampling system. The recommended maximum leakage rate on the pressure side is five percent of the in-use flow rate.