Protection of Environment. Part1054:Control of emissions from new, small nonroad spark-ignition engines and equipment. Section1054.505:How do I test engines?
(a) This section describes how to test engines under steady-state conditions. For handheld engines you must perform tests with discrete-mode sampling. For nonhandheld engines we allow you to perform tests with either discrete-mode or ramped-modal testing methods, as described in 40 CFR Part 1065. You must use the same modaltesting method for certification and all other testing you perform for an enginefamily. If we test your engines to confirm that they meet emission standards,we will use the modal testing method you select for your own testing. If you submit certification test data collected with both discrete-mode and ramped-modal testing (either in your original application or in an amendment to your application), eithermethod may be used for subsequent testing. We may also perform other testing as allowed by the Clean Air Act. Conduct duty-cycle testing as follows: