Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p24
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 24/108)
Character Range: 951341–954402

be set according to paragraph 2.5.3. of this annex. If the chassis dynamometer is not capable to meet the inertia setting exactly, the next higher inertia setting shall be applied with a maximum increase of 10 kg.
              7.2.2. Chassis dynamometer warm-up
              The chassis dynamometer shall be warmed up in accordance with the dynamometer manufacturer's recommendations, or as appropriate, so that the frictional losses of the dynamometer may be stabilized.
              7.3. Vehicle preparation
              7.3.1. Tyre pressure adjustment
              The tyre pressure at the soak temperature of a Type 1 test shall be set to no more than 50 per cent above the lower limit of the tyre pressure range for the selected tyre, as specified by the vehicle manufacturer (see paragraph 4.2.2.3. of this annex), and shall be recorded.
              7.3.2. If the determination of dynamometer settings cannot meet the criteria described in paragraph 8.1.3. of this annex due to non-reproducible forces, the vehicle shall be equipped with a vehicle coastdown mode. The coastdown mode shall be approved by the responsible authority and its use shall be included in all relevant test reports.
              If a vehicle is equipped with a vehicle coastdown mode, it shall be engaged both during road load determination and on the chassis dynamometer.
              7.3.3. Vehicle placement on the dynamometer
              The tested vehicle shall be placed on the chassis dynamometer in a straight ahead position and restrained in a safe manner.

              7.3.3.1. In the case that a single roller chassis dynamometer is used, the vehicle shall be positioned and stay positioned throughout the procedure according to the requirements in 7.3.3.1.1. to 7.3.3.1.3.

              7.3.3.1.1. Rotational alignment (rotation around z-axis)

               The vehicle shall be positioned in line with the x-axis in order to minimise rotation around the z-axis

              7.3.3.1.2. Lateral position (y-axis)

               The vehicle shall remain aligned in the y-direction and lateral movement shall be minimised.

              7.3.3.1.3. Front and rear position (x-axis)

               For all rotating wheels the centre of the tyre's contact patch on the roller shall be within ±25 mm or ±2 per cent of the roller diameter, whichever is smaller, from the top of the roller.

              7.3.3.1.4. The tested vehicle shall be restrained with a system compliant with paragraph 2.3.2. of Annex B5 .

               If the torque meter method is used, the tyre pressure shall be adjusted such that the dynamic radius is within 0.5 per cent of the dynamic radius rj calculated using the equations in paragraph 4.4.3.1. of this annex at the 80 km/h reference speed point. The dynamic radius on the chassis dynamometer shall be calculated according to the procedure described in paragraph 4.4.3.1. of this annex.

              If this adjustment is outside the range defined in paragraph 7.3.1. of this annex, the torque meter method shall not