Document ID: chunk:federal_register_of_legislation:F2023L01529:body:0:p42
Version: federal_register_of_legislation:F2023L01529
Segment Type: other
Provision Reference: 
Character Range: 116656–119734

this phase, the charger shall supply maximum current as recommended by the manufacturer.

       5.2.5.10. The hydrogen analyser shall be zeroed and spanned immediately before the end of the test.

       5.2.5.11. The end of test period occurs t'1 + 30 minutes after the beginning of the initial sampling, as specified in paragraph 5.2.5.8. above. The times elapsed are recorded. The hydrogen concentration, temperature and barometric pressure are measured to give the final readings CH2f, Tf and Pf for the charging failure test, used for the calculation in paragraph 6. below.

       6. Calculation

        The hydrogen emission tests described in paragraph 5. above allow the calculation of the hydrogen emissions from the normal charge and charging failure phases.  Hydrogen emissions from each of these phases are calculated using the initial and final hydrogen concentrations, temperatures and pressures in the enclosure, together with the net enclosure volume.

        The formula below is used:

       Where :

              MH2 = hydrogen mass, in grams

                     CH2 = measured hydrogen concentration in the enclosure, in ppm volume

                     V = net enclosure volume in cubic metres (m3) corrected for the volume of the vehicle, with the windows and the luggage compartment open.  If the volume of the vehicle is not determined a volume of 1.42 m³ is subtracted.

                     Vout = compensation volume in m³, at the test temperature and pressure

                     T = ambient chamber temperature, in K

                     P = absolute enclosure pressure, in kPa

                     k = 2.42

       Where:

       i is the initial reading

        f is the final reading

       6.1. Results of test

        The hydrogen mass emissions for the REESS are:

       MN = hydrogen mass emission for normal charge test, in grams

        MD = hydrogen mass emission for charging failure test, in grams.

Annex 7 ‑ Appendix 1

Calibration of equipment for hydrogen emission testing

       1. Calibration frequency and methods

        All equipment shall be calibrated before its initial use and then calibrated as often as necessary and in any case in the month before type approval testing.  The calibration methods to be used are described in this appendix.

       2. Calibration of the enclosure

       2.1. Initial determination of enclosure internal volume

       2.1.1. Before its initial use, the internal volume of the chamber shall be determined as follows.  The internal dimensions of the chamber are carefully measured, taking into account any irregularities such as bracing struts.  The internal volume of the chamber is determined from these measurements.

       The enclosure shall be latched to a fixed volume when the enclosure is held at an ambient temperature of 293 K.  This nominal volume shall be repeatable within ±0.5 per cent of the reported value.

       2.1.2. The net internal volume is determined by subtracting 1.42 m3 from the internal volume of the chamber.  Alternatively the volume of