Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p25
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 25/71)
Character Range: 279233–282364

filters or reference filter pairs shall be weighed within 4 hours of, but preferably at the same time as the sample filter (pair) weighings. They shall be the same size and material as the sample filters.

              If the average weight of the reference filters (reference filter pairs) changes between sample filter weighings by more than ± 5 % (± 7,5 % for the filter pair respectively) of the recommended minimum filter loading (Section 4.1.5), then all sample filters shall be discarded and the emissions test repeated.

              If the weighing room stability criteria outlined in Section 4.2.1 is not met, but the reference filter (pair) weighings meet the above criteria, the engine manufacturer has the option of accepting the sample filter weights or voiding the tests, fixing the weighing room control system and rerunning the test.

4.2.3.                        Analytical balance

              The analytical balance used to determine the weights of all filters shall have a precision (standard deviation) of 20 μg and a resolution of 10 μg (1 digit = 10 μg). For filters less than 70 mm diameter, the precision and resolution shall be 2 μg and 1 μg, respectively.

4.3.                            Additional specifications for particulate measurement

              All parts of the dilution system and the sampling system from the exhaust pipe up to the filter holder, which are in contact with raw and diluted exhaust gas, must be designed to minimise deposition or alteration of the particulates. All parts must be made of electrically conductive materials that do not react with exhaust gas components, and must be electrically grounded to prevent electrostatic effects.

5.                                DETERMINATION OF SMOKE

              This section provides specifications for the required and optional test equipment to be used for the ELR test. The smoke shall be measured with an opacimeter having an opacity and a light absorption coefficient readout mode. The opacity readout mode shall only be used for calibration and checking of the opacimeter. The smoke values of the test cycle shall be measured in the light absorption coefficient readout mode.

5.1.                            General requirements

              The ELR requires the use of a smoke measurement and data processing system which includes three functional units. These units may be integrated into a single component or provided as a system of interconnected components. The three functional units are:

                —    an opacimeter meeting the specifications of Annex V, Section 3,
                —    a data processing unit capable of performing the functions described in Annex III, Appendix 1, Section 6,
                —    a printer and/or electronic storage medium to record and output the required smoke values specified in Annex III, Appendix 1, Section 6.3.

5.2.                            Specific requirements

5.2.1.                        Linearity

              The linearity shall be within ± 2 % opacity.

5.2.2.                        Zero drift

              The zero drift during a one