Document ID: chunk:federal_register_of_legislation:F2012C00283:reg:20:p10
Version: federal_register_of_legislation:F2012C00283
Segment Type: reg
Provision Reference: reg 20 (pt 10/19)
Character Range: 220806–223827

80 km/h and the absorbed power at 50 km/h shall be noted.
               Dynamometer with adjustable load curve: the load simulator shall be adjusted in order to absorb the power exerted on the driving wheels at steady speeds of 120, 100, 80, 60 and 40 and 20 km/h.
              6.2.1.2. Load determined by vehicle reference mass
               With the manufacturer's agreement the following method may be used.
               The brake is adjusted so as to absorb the load exerted at the driving wheels at a constant speed of 80 km/h, in accordance with Table 3.
               If the corresponding equivalent inertia is not available on the dynamometer, the larger value closest to the vehicle reference mass will be used.
               In the case of vehicles other than passenger cars, with a reference mass of more than 1,700 kg or vehicles with permanent all-wheel drive, the power values given in Table 3 are multiplied by a factor 1.3.
              6.2.1.3. The method used and the values obtained (equivalent inertia - characteristic adjustment parameter) shall be recorded in the test report.
              6.2.2. Preliminary testing cycles
               Preliminary testing cycles should 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 under which the cycle is carried out.
              6.2.3. Tyre pressures
               The tyre pressures shall be the same as that specified by the manufacturer and used for the preliminary road test for brake adjustment. The tyre pressure may be increased by up to 50 per cent from the manufacturer's recommended setting in the case of a two-roller dynamometer. The actual pressure used shall be recorded in the test report.
              6.2.4. Background particulate mass measurement
               The particulate background level of the dilution air may be determined by passing filtered dilution air through the particulate filter. This shall be drawn from the same point as the particulate sample. One measurement may be performed prior to or after the test. Particulate mass measurements may be corrected by subtracting the background contribution from the dilution system. The permissible background contribution shall be ≤ 1mg/km (or equivalent mass on the filter). If the background exceeds this level, the default figure of 1 mg/km (or equivalent mass on the filter) shall be employed. Where subtraction of the background contribution gives a negative result, the particulate mass result shall be considered to be zero.
              6.2.5. Background particle number measurements
               The subtraction of background particle numbers may be determined by sampling dilution air drawn from a point downstream of the particle and hydrocarbon filters into the particle number measurement system. Background correction of particle number measurements shall not be allowed for type approval, but may be used at