Document ID: chunk:federal_register_of_legislation:F2021C01192:body:0:p50
Version: federal_register_of_legislation:F2021C01192
Segment Type: other
Provision Reference: 
Character Range: 132191–134797

15 km/h, according to the following formula:

1.2.3.  The coefficient of adhesion kM shall be determined by weighting with the dynamic axle loads.

 where:

1.2.4.  The value of  shall be rounded to two decimal places.
1.2.5.  In the case of a vehicle equipped with an anti-lock system of categories 1 or 2, the value of zAL will be based on the whole vehicle, with the anti-lock system in operation, and the adhesion utilized () is given by the same formula quoted in paragraph 1.2.1. of this appendix.
1.2.6.  In the case of a vehicle equipped with an anti-lock system of category 3, the value of zAL will be measured on each axle which has at least one directly controlled wheel. For example, for a two-axle rear-wheel drive vehicle with an anti-lock system acting only on the rear axle (2), the adhesion utilized () is given by:

  This calculation shall be made for each axle having at least one directly controlled wheel.
1.3.  If  > 1.00, the measurements of coefficients of adhesion shall be repeated. A tolerance of 10% is accepted.
Annex 6 - Appendix 3
  Performance on differing adhesion surfaces
1.  The prescribed braking rate referred to in paragraph 5.3.5. of this annex may be calculated by reference to the measured coefficient of adhesion of the two surfaces on which this test is carried out. These two surfaces shall satisfy the conditions prescribed in paragraph 5.3.4. of this annex.
2.  The coefficient of adhesion ( kH and kL ) of the high- and low-adhesion surfaces, respectively, shall be determined in accordance with the provisions in paragraph 1.1. of Appendix 2 to this annex.
3.  The braking rate (zMALS) for laden vehicles shall be:

Annex 6 - Appendix 4
  Method of selection of the low adhesion surface
1.  Details of the coefficient of adhesion of the surface selected, as defined in paragraph 5.1.1.2. of this annex, shall be given to the Technical Service.
1.1.  These data shall include a curve of the coefficient of adhesion versus slip (from 0 to 100 per cent slip) for a speed of approximately 40 km/h.
1.1.1.  The maximum value of the curve will represent kpeak  and the value at 100 per cent slip will represent klock .
1.1.2.  The ratio R shall be determined as the quotient of the kpeak and klock.

1.1.3.  The value of R shall be rounded to one decimal place.
1.1.4.  The surface to be used shall have a 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