Document ID: chunk:federal_register_of_legislation:F2022C00213:reg:120:p1
Version: federal_register_of_legislation:F2022C00213
Segment Type: reg
Provision Reference: reg 120 (pt 1/56)
Character Range: 156219–159046

120       1.57 . 10-4  0.14

         6.2. Setting of the dynamometer

           The purpose of this procedure is to simulate on the dynamometer the total road load power at a given speed.

         6.2.1.  Measurement equipment and accuracy

           The measuring equipment shall be similar to that used on the track.

         6.2.2.  Test procedure

         6.2.2.1. Install the vehicle on the dynamometer.

         6.2.2.2. Adjust the tyre pressure (cold) of the driving wheels as required for the chassis dynamometer.

6.2.2.3. Adjust the equivalent inertia mass of the chassis dynamometer, according to table 2.

Table 2

 Test mass             Equivalent inertia
 MHP                   I
 (kg)                  (kg)
        MHP < 480      455
 480 < MHP < 540       510
 540 < MHP < 595       570
 595 < MHP < 650       625
 650 < MHP < 710       680
 710 < MHP < 765       740
 765 < MHP < 850       800
 850 < MHP < 965       910
 965 < MHP < 1,080     1,020
 1,080 < MHP < 1,190   1,130
 1,190 < MHP < 1,305   1,250
 1,305 < MHP < 1,420   1,360
 1,420 < MHP < 1,530   1,470
 1,530 < MHP < 1,640   1,590
 1,640 < MHP < 1,760   1,700
 1,760 < MHP < 1,870   1,810
 1,870 < MHP < 1,980   1,930
 1,980 < MHP < 2,100   2,040
 2,100 < MHP < 2,210   2,150
 2,210 < MHP < 2,380   2,270
 2,380 < MHP < 2,610   2,270
 2,610 < MHP           2,270

         6.2.2.4. Bring the vehicle and the chassis dynamometer to the stabilized operating temperature, in order to approximate the road conditions.

         6.2.2.5. Carry out the operations specified in paragraph 6.1.2. to this annex with the exception of paragraphs 6.1.2.4. and 6.1.2.5., replacing MHP by I and Mr by Mrm in the formula given in paragraph 6.1.2.7.

         6.2.2.6. Adjust the brake to reproduce the corrected running resistance half payload (paragraph 6.1.2.8. to this annex) and to take into account the difference between the vehicle mass on the track and the equivalent inertia test mass (I) to be used.  This may be done by calculating the mean corrected road coast down time from V2 to V1 and reproducing the same time on the dynamometer by the following relationship:

          where:

               I is the flywheel equivalent inertia mass of chassis dynamometer.

                    Mrm is the equivalent inertia mass of the powered wheels and vehicle portions rotating with the wheels during coast down.  Mrm shall be measured or calculated by an appropriate manner.

         6.2.2.7. The power Pa to be absorbed by the bench should be determined in order to enable the same total road load power to be reproduced for the same vehicle on different days or on different chassis dynamometers of the same type.

Annex 8

    METHOD OF MEASURING THE EMISSIONS OF CARBON DIOXIDE, FUEL CONSUMPTION AND THE ELECTRIC ENERGY CONSUMPTION