Document ID: chunk:federal_register_of_legislation:F2021C01192:body:0:p52
Version: federal_register_of_legislation:F2021C01192
Segment Type: other
Provision Reference: 
Character Range: 137058–139833

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 row (A) of the table under paragraph 2.1.1. 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 row (A) of the table under paragraph 2.1.1. 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 shall not have exceeded a temperature of 180 °C during the bedding procedure, or alternatively, at the vehicle manufacturer's request, be bedded in accordance with his recommendations.
3.4.  Cooling air may be used, flowing over the brake in a direction perpendicular to its axis of rotation. The velocity of the cooling air flowing over the brake shall be not greater than 10 km/h. The temperature of the cooling air shall be the ambient temperature.
4.  Test procedure
4.1.  Five sample sets of the brake lining shall be subjected to the comparison test; they shall be compared with five sets of linings conforming to the original components identified in the information document concerning the first approval of the vehicle type concerned.
4.2.  Brake lining equivalence shall be based on a comparison of the results achieved using the test procedures prescribed in this annex and in accordance with the following requirements.
4.3.   Type-O cold performance test
4.3.1.  Three brake applications shall be made when the initial temperature is below 100 °C. The temperature shall be measured in accordance with the provisions of paragraph 2.1.4.4. of this annex.
4.3.2.  Brake applications shall be made from an initial rotational speed equivalent