Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p100
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 100/108)
Character Range: 1171739–1174648

ambient temperature around the vehicle and shall be checked by the technical service.

              The sensor shall be at least 10 cm away from the wall of the soak area and shall be shielded from direct air flow.

              The air-flow conditions within the soak room in the vicinity of the vehicle shall represent a natural convection flow representative for the dimension of the room (no forced convection).

              3.3. Test vehicle

              3.3.1. The vehicle to be tested shall be representative of the family for which the ATCT data are determined (as described in paragraph 2.1. of this Annex B6a).

              3.3.2.  From the ATCT Family, the Interpolation Family with the lowest engine capacity shall be selected (see paragraph 2 of this Annex B6a), and the test vehicle shall be in the 'vehicle H' configuration of this family.

              3.3.3. Where applicable, the vehicle with the lowest enthalpy of the active heat storage device and the slowest heat release for the active heat storage device from the ATCT Family shall be selected.

              3.3.4. The test vehicle shall meet the requirements detailed in paragraph 2.3. of Annex B6 and paragraph 2.1 of this Annex B6a.

              3.4. Settings

              3.4.1. Road load and dynamometer settings shall be as specified in Annex B4, including the requirement for the room temperature to be at 23 oC.

              To take account of the difference in air density at 14 oC when compared to the air density at 20 oC, the chassis dynamometer shall be set as specified in paragraphs 7. and 8. of Annex B4 with the exception that f2_TReg from the following equation shall be used as the target coefficient Ct.

              f2_TReg = f2 * (Tref + 273)/(Treg + 273)

              where:

                  f2 is the second order road load coefficient, at reference conditions, N/(km/h)2;

                  Tref is the road load reference temperature as specified in paragraph 3.2.10. of this Regulation, C;

                  Treg is the regional temperature, as defined in paragraph 3.1.1. of this Annex B6a, C.

              In the case that a valid chassis dynamometer setting of the 23 °C test is available, the second order chassis dynamometer coefficient of Cd shall be adapted in accordance with the following equation:

              Cd_Treg = Cd + (f2_TReg – f2)

              3.4.2. The ATCT test and its road load setting shall be performed on a 2WD dynamometer in the case that the corresponding Type 1 test was done on a 2WD dynamometer; and it shall be performed on a 4WD dynamometer in the case that the corresponding Type 1 test was done on a 4WD dynamometer.

              3.5. Preconditioning

              At the request of the manufacturer preconditioning may be undertaken at Treg.

              The engine temperature shall be within ± 2 °C of the set point of 23 °C or Treg,