Document ID: chunk:federal_register_of_legislation:F2023C00919:body:0:p100
Version: federal_register_of_legislation:F2023C00919
Segment Type: other
Provision Reference: 
Character Range: 293629–296749

the test poses particular problems, provided such calculations are clearly valid.
5.4.1.                              M1 category vehicles with conventional suspension
With the vehicle standing on the measuring site and, if necessary, with the wheels resting on floating platforms (which shall be used if their absence would lead to restriction of the suspension movement likely to affect the results of measurements), rock the vehicle continuously for at least three complete cycles, for each cycle, first the rear and then the front end of the vehicle is pushed down.
The rocking sequence shall end with the completion of a cycle. Before making the measurements, the vehicle shall be allowed to come to rest spontaneously.  Instead of using floating platforms, the same effect can be achieved by moving the vehicle backwards and forwards for at least a complete wheel revolution.
5.4.2.                              M2, M3 and N category vehicles with conventional suspension
5.4.2.1.                        If the treatment method for category M1 vehicles described in paragraph 5.4.1. is not possible, the method described in paragraphs 5.4.2.2. or 5.4.2.3. may be used.
5.4.2.2.                        With the vehicle standing on the measuring site and the wheels on the ground, rock the vehicle by temporarily varying the load.
5.4.2.3.                        With the vehicle standing on the measuring site and the wheels on the ground, activate the vehicle suspension and all other parts, which may affect the dipped beam inclination by using a vibration rig.  This can be a vibrating platform on which the wheels rest.
5.4.3.                              Vehicles with non-conventional suspension, where the engine has to be running.
Before making any measurement wait until the vehicle has assumed its final attitude with the engine running.
5.5.                                    Measurements
The variation of the inclination of the dipped beam shall be assessed for each of the different loading conditions in relation to the measured initial inclination determined in accordance with paragraph 5.2. above.
If the vehicle is fitted with a manual headlamp levelling system, the latter shall be adjusted to the positions specified by the manufacturer for given loading conditions (according to Annex 5).
5.5.1.                              To begin with, a single measurement shall be made in each loading condition. Requirements have been met if, for all the loading conditions, the variation in inclination is within the calculated limits (for example, within the difference between the stated initial inclination and the lower and upper limits specified for approval) with a safety margin of 4 mrad (0.4 per cent inclination).
5.5.2.                              If the result(s) of any measurement(s) does (do) not lie within the safety margin indicated in paragraph 5.5.1. or exceed(s) the limit values, a further three measurements shall be made in the loading conditions corresponding to this (these) result(s) as specified in paragraph 5.5.3.
5.5.3.                              For each of the above