CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 91—CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES > SUBPART D—Emission Test Equipment Provisions (§91.301 to §91.329) > 91.328—Measurement equipment accuracy/calibration frequency table.

91.328—Measurement equipment accuracy/calibration frequency table.

(a) The accuracy of measurements must be such that the maximum tolerances shown in Table 2 in appendix A to this subpart are not exceeded.
(b) Calibrate all equipment and analyzers according to the frequencies shown in Table 2 in appendix A to this subpart.
(c) Prior to initial use and after major repairs, bench check each analyzer (see § 91.323 ).
(d) Calibrate as specified in § 91.306 and §§ 91.315 through 91.322.
(e) At least monthly, or after any maintenance which could alter calibration, perform the following calibrations and checks.
(1) Leak check the vacuum side of the system (see § 91.324(a) ).
(2) Verify that the automatic data collection system (if used) meets the requirements found in Table 2 in appendix A to this subpart.
(3) Check the fuel flow measurement instrument to insure that the specifications in Table 2 in appendix A to this subpart are met.
(f) Verify that all NDIR analyzers meet the water rejection ratio and the CO2 rejection ratio as specified in § 91.325.
(g) Verify that the dynamometer test stand and power output instrumentation meet the specifications in Table 2 in appendix A to this subpart.