Document ID: chunk:federal_register_of_legislation:F2024C00356:reg:12:p5
Version: federal_register_of_legislation:F2024C00356
Segment Type: reg
Provision Reference: reg 12 (pt 5/10)
Character Range: 461457–464423

linear velocity of the air at the blower outlet is within 5 km/h of the corresponding roller speed. The final selection of the blower shall have the following characteristics:
                   (i) Area: at least 0.2 m2;
                   (ii) Height of the lower edge above ground: approximately 20 cm.
               As an alternative the blower linear air speed shall be at least 6 m/s (21.6 km/h). At the request of the manufacturer, for special vehicles (e.g. vans, off-road) the height of the cooling fan may be modified.
              5.2.1.4. The vehicle speed as measured from the dynamometer roll(s) shall be used (paragraph 1.2.6. of Appendix 1 of Annex 4a).
              5.2.3. Preliminary testing cycles may be carried out if necessary, to determine how best to actuate the accelerator and brake controls so as to achieve a cycle approximating to the theoretical cycle within the prescribed limits, or to permit sampling system adjustment. Such driving shall be carried out before "START" according to Figure 8/1.
              5.2.4. Humidity in the air shall be kept low enough to prevent condensation on the dynamometer roll(s).
              5.2.5. The dynamometer shall be thoroughly warmed as recommended by the dynamometer manufacturer, and using procedures or control methods that assure stability of the residual frictional power.
              5.2.6. The time between dynamometer warming and the start of the emission test shall be no longer than 10 minutes if the dynamometer bearings are not independently heated. If the dynamometer bearings are independently heated, the emission test shall begin no longer than 20 minutes after dynamometer warming.
              5.2.7. If the dynamometer power is to be adjusted manually, it shall be set within one hour prior to the exhaust emission test phase. The test vehicle may not be used to make the adjustment. The dynamometer, using automatic control of pre-selectable power settings, may be set at any time prior to the beginning of the emission test.
              5.2.8. Before the emission test driving schedule may begin, the test cell temperature shall be 266 K (-7 °C) 2 K, as measured in the air stream of the cooling fan with a maximum distance of 1.5 m from the vehicle.
              5.2.9. During operation of the vehicle the heating and defrosting devices shall be shut off.
              5.2.10. The total driving distance or roller revolutions measured are recorded.
              5.2.11. A four-wheel drive vehicle shall be tested in a two-wheel drive mode of operation. The determination of the total road force for dynamometer setting is performed while operating the vehicle in its primary designed driving mode.
              5.3. Performing the test
              5.3.1. The provisions of paragraph 6.4., excluding 6.4.1.2., of Annex 4a apply in respect of starting the engine, carrying out the test and taking the emission samples. The sampling begins before or at the