Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p6
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 6/56)
Character Range: 311892–314553

for the hot start test using a 10 ± 1 minute hot soak period.

7.6.4. Hot start test

 The engine shall be started at the end of the hot soak period as defined in paragraph 7.6.3. using the starting methods given in paragraph 7.6.2.

7.6.5. Test sequence

 The test sequence of both cold start and hot start test shall commence at the start of the engine. After the engine is running, cycle control shall be initiated so that engine operation matches the first set point of the cycle.

 The WHTC shall be performed according to the reference cycle as set out in paragraph 7.4. Engine speed and torque command set points shall be issued at 5 Hz (10 Hz recommended) or greater. The set points shall be calculated by linear interpolation between the 1 Hz set points of the reference cycle. Actual engine speed and torque shall be recorded at least once every second during the test cycle (1 Hz), and the signals may be electronically filtered.

7.6.6. Collection of emission relevant data

 At the start of the test sequence, the measuring equipment shall be started, simultaneously:
(a) Start collecting or analyzing diluent, if a full flow dilution system is used;
(b) Start collecting or analyzing raw or diluted exhaust gas, depending on the method used;
(c) Start measuring the amount of diluted exhaust gas and the required temperatures and pressures;
(d) Start recording the exhaust gas mass flow rate, if raw exhaust gas analysis is used;
(e) Start recording the feedback data of speed and torque of the dynamometer.

 If raw exhaust measurement is used, the emission concentrations ((NM)HC, CO and NOx) and the exhaust gas mass flow rate shall be measured continuously and stored with at least 2 Hz on a computer system. All other data may be recorded with a sample rate of at least 1 Hz. For analogue analyzers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation.

 If a full flow dilution system is used, HC and NOx shall be measured continuously in the dilution tunnel with a frequency of at least 2 Hz. The average concentrations shall be determined by integrating the analyzer signals over the test cycle. The system response time shall be no greater than 20 seconds, and shall be coordinated with CVS flow fluctuations and sampling time/test cycle offsets, if necessary. CO, CO2, and NMHC may be determined by integration of continuous measurement signals or by analyzing the concentrations in the sample bag, collected over the cycle. The concentrations of the gaseous pollutants in the diluent shall be determined prior to the point where the exhaust enters into the dilution tunnel