Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p14
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 14/30)
Character Range: 559080–561903

from the preconditioning, the measuring equipment shall be started, simultaneously:

              - start analysing the raw exhaust gas concentrations,

              - start measuring the exhaust gas or intake air and fuel flow rate,

              - start recording the feedback data of speed and torque of the dynamometer.

              For the evaluation of the gaseous emissions, the emission concentrations (HC, CO and NOx) and the exhaust gas mass flow rate shall be recorded and stored with at least 2 Hz on a computer system. The system response time shall be no greater than 10 s. All other data may be recorded with a sample rate of at least 1 Hz. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation.

              For calculation of the mass emission of the gaseous components the traces of the recorded concentrations and the trace of the exhaust gas mass flow rate shall be time aligned by the transformation time as defined in section 2 of Annex I. Therefore, the response time of each gaseous emissions analyser and of the exhaust gas mass flow system shall be determined according to the provisions of section 4.2.1 and section 1.5 of Appendix 5 to this Annex and recorded.

        3.8.3. Particulate sampling (if applicable)

        3.8.3.1. Full flow dilution system

              At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the particulate sampling system shall be switched from by-pass to collecting particulates.

              If no flow compensation is used, the sample pump(s) shall be adjusted so that the flow rate through the particulate sample probe or transfer tube is maintained at a value within ± 5 % of the set flow rate. If flow compensation (i.e., proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ± 5 % of its set value (except for the first 10 seconds of sampling).

              Note: For double dilution operation, sample flow is the net difference between the flow rate through the sample filters and the secondary dilution air flow rate.

              The average temperature and pressure at the gas meter(s) or flow instrumentation inlet shall be recorded. If the set flow rate can- not be maintained over the complete cycle (within ± 5 %) because of high particulate loading on the filter, the test shall be voided. The test shall be rerun using a lower flow rate and/or a larger diameter filter.

        3.8.3.2. Partial flow dilution system

              At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the particulate sampling system shall be switched