Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p16
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 16/30)
Character Range: 564135–566949

III.

        3.8.4. Engine stalling

              If the engine stalls anywhere during the test cycle, the engine shall be preconditioned and restarted, and the test repeated. If a mal- function occurs in any of the required test equipment during the test cycle, the test shall be voided.

        3.8.5. Operations after test

              At the completion of the test, the measurement of the diluted exhaust gas volume or raw exhaust gas flow rate, the gas flow into the collecting bags and the particulate sample pump shall be stopped. For an integrating analyser system, sampling shall continue until system response times have elapsed.

              The concentrations of the collecting bags, if used, shall be analysed as soon as possible and in any case not later than 20 minutes after the end of the test cycle.

              After the emission test, a zero gas and the same span gas shall be used for re-checking the analysers. The test will be considered acceptable if the difference between the pre-test and post-test results is less than 2 % of the span gas value.

        3.9.  Verification of the test run

        3.9.1. Data shift

              To minimise the biasing effect of the time lag between the feedback and reference cycle values, the entire engine speed and torque feedback signal sequence may be advanced or delayed in time with respect to the reference speed and torque sequence. If the feed- back signals are shifted, both speed and torque must be shifted the same amount in the same direction.

        3.9.2. Calculation of the cycle work

              The actual cycle work Wact (kWh) shall be calculated using each pair of engine feedback speed and torque values recorded. This shall be done after any feedback data shift has occurred, if this option is selected. The actual cycle work Wact is used for compari- son to the reference cycle work Wref and for calculating the brake specific emissions (see sections 4.4 and 5.2). The same meth- odology shall be used for integrating both reference and actual engine power. If values are to be determined between adjacent reference or adjacent measured values, linear interpolation shall be used.

              In integrating the reference and actual cycle work, all negative torque values shall be set equal to zero and included. If integration is performed at a frequency of less than 5 Hertz, and if, during a given time segment, the torque value changes from positive to negative or negative to positive, the negative portion shall be computed and set equal to zero. The positive portion shall be included in the integrated value.

Wact shall be between – 15 % and + 5 % of Wref

        3.9.3. Validation statistics of the test cycle

              Linear regressions of the feedback values on the reference values shall