Document ID: chunk:federal_register_of_legislation:F2021C00476:body:0:p54
Version: federal_register_of_legislation:F2021C00476
Segment Type: other
Provision Reference: 
Character Range: 149932–152942

information document, a model of which is given in Annex 1 to this Regulation.

         1.3.  The Technical Authority responsible for conducting approval tests may at its discretion require comparison of the performance of the brake linings to be carried out in accordance with the relevant provisions contained in Annex 3 to this Regulation.

         1.4.  Application for approval by comparison shall be made by the vehicle manufacturer or by his duly accredited representative.

         1.5.  In the context of this annex "vehicle" shall mean the vehicle type approved according to this Regulation and for which it is requested that the comparison shall be considered satisfactory.

         2.  TEST EQUIPMENT

         2.1.  A dynamometer having the following characteristics shall be used for the tests:

         2.1.1.  it shall be capable of generating the inertia required by paragraph 3.1. of this annex, and have the capacity to meet the requirements prescribed by paragraph 1.5. of Annex 3 to this Regulation with respect to the Type-I fade test;

         2.1.2.  the brakes fitted shall be identical with those of the original vehicle type concerned;

         2.1.3.  air cooling, if provided, shall be in accordance with paragraph 3.4. of this annex;

         2.1.4.  the instrumentation for the test shall be capable of providing at least the following data;

         2.1.4.1.  a continuous recording of disc or drum rotational speed;

         2.1.4.2.  number of revolutions completed during a stop, to resolution not greater than one eighth of a revolution;

         2.1.4.3.  stop time;

         2.1.4.4.  a continuous recording of the temperature measured in the centre of the path swept by the lining or at mid-thickness of the disc or drum or lining;

         2.1.4.5.  a continuous recording of brake application control line pressure or force;

         2.1.4.6.  a continuous recording of brake output torque.

         3.   TEST CONDITIONS

         3.1.  The dynamometer shall be set as close as possible, with  5 per cent tolerance, to the rotary inertia equivalent to that part of the total inertia of the vehicle braked by the appropriate wheel(s) according to the following formula:

         I = M R2

           where:

              I = rotational inertia (kgm2 )

              R = dynamic tyre rolling radius (m)

              M = that part of the maximum mass of the vehicle braked by the appropriate wheel(s).  In the case of a single-ended dynamometer, this part shall be calculated from the design braking distribution when deceleration corresponds to the appropriate value given in paragraph 2.1.1.(A) of Annex 3 to this Regulation.

         3.2.  The initial rotational speed of the inertia dynamometer shall correspond to the linear speed of the vehicle as prescribed in paragraph 2.1.1.(A) of Annex 3 to this Regulation and shall be based on the dynamic rolling radius of the tyre.

         3.3.  Brake linings shall be at least 80 per cent bedded and