Document ID: chunk:federal_register_of_legislation:F2021C01192:body:0:p51
Version: federal_register_of_legislation:F2021C01192
Segment Type: other
Provision Reference: 
Character Range: 134553–137324

ratio R between 1.0 and 2.0.[25]
2.  Prior to the tests, the Technical Service shall ensure that the selected surface meets the specified requirements and shall be informed of the following:
 Test method to determine R,
 Type of vehicle,
  Axle load and tyres (different loads and different tyres have to be tested and the results shown to the Technical Service which will decide if they are representative for the vehicle to be approved).
2.1.  The value of R shall be mentioned in the test report.
  The calibration of the surface has to be carried out at least once a year with a representative vehicle to verify the stability of R.
Annex 7
  Inertia dynamometer test method for brake linings
1.  General
1.1.  The procedure described in this annex may be applied in the event of a modification of vehicle type resulting from the fitting of brake linings of another type to vehicles which have been approved in accordance with this Regulation.
1.2.  The alternative types of brake linings shall be checked by comparing their performance with that obtained from the brake linings with which the vehicle was equipped at the time of approval and conforming to the components identified in the relevant 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