Document ID: chunk:federal_register_of_legislation:F2023C00157:body:0:p13
Version: federal_register_of_legislation:F2023C00157
Segment Type: other
Provision Reference: 
Character Range: 33533–36269

the gun immediately before use.

       2.2. The photometric measuring equipment shall be equivalent to that used in connection with the approval of headlamps.

       2.3. A power supply of sufficient capacity (during the cleaning period the voltage drop must not be more than 1%), a voltmeter for short time measurements (oscillograph), a spray gun at an operating pressure of about 500 kPa with a flow cup and a nozzle of 1.5 mm diameter.

       2.4. If not tested on the vehicle, the headlamp(s) and the cleaner shall be mounted on a test fixture which reproduces the installation on the vehicle and permits normal operation of both cleaner and headlamp (s).

       2.5. For the purpose of the test on electrically operated devices the power supply shall be adjusted in such a way that under load at the contacts of the largest consumer the voltage is 13.0 V in the case or 12 V systems and 27.0 V in the case of 24 V systems. As far as the measurements of illumination are concerned, they shall be carried out on the basis    of the approval tests for the headlamps.  In case of doubt only measurements performed with a standard filament lamp are valid.

       3. Photometric measurements of the headlamp when clean

         The light-emitting surface of the headlamp shall be clean and the headlamp cleaner shall be in the stationary position.  The photometric measurements shall be made in compliance with the specifications of the relevant Regulation, as well as the measurements prescribed in paragraph 4 below. The illumination shall then be measured at the measuring points specified in paragraph 7 of this Regulation.

       4. Evaluation of cleaning efficiency

       4.1. After the headlamp(s) has been operated for 10 minutes the dirt mixture shall be applied evenly to its entire light-emitting surface using the spray gun mentioned above. The mixture shall then be dried either by operating the headlamp or using hot air. This procedure shall be repeated, if necessary until the luminous intensity in all measuring points has been reduced below 20 % of the values according to paragraph 3 of this annex. At least the luminous intensity in one of the several measuring points shall be between 15 and 20 %.

       4.1.1. The values to be used during the tests for the duration of the cleaning period and the consumption of cleaning fluid during this period shall be the values declared by the manufacturer. The fluid consumption shall be measured as the mean value over several cleaning periods as specified by the manufacturer.

       4.1.2. After the headlamp has cooled down and not later than two hours after the dirt has dried the headlamps shall be switched on and the headlamp cleaner shall be operated for