Preparation of the Headlamp. 1.2.1.1 Test mixture The mixture of water and a polluting agent to be applied to the headlamp shall be composed of nine parts (by weight) of silica sand with a grain size distributed between 0 and 100 um, one part (by weight) of vegetal carbon dust of a grain size distributed between 0 and 100 µm, 0.2 part (by weight) of NaCMC and an appropriate quantity of distilled water, the conductivity of which is lower than 1 mS/m for the purpose of this test. The mixture must not be more than 14 days old.
1.2.1.2 Application of the test mixture to the headlamp The test mixture shall be uniformly applied to the entire light emitting surface of the headlamp and then left to dry. This procedure shall be repeated until the illumination value has dropped to 15-20 per cent of the values measured for each following point under the conditions described in this annex: Point of Emax in driving beam, photometric distribution for a driving/passing lamp, Point of Emax in driving beam, photometric distribution for a driving lamp only, 50 R and 50 V for a passing lamp only, designed for right-hand traffic, 50 L and 50 V for a passing lamp only, designed for left-hand traffic.
Preparation of the Headlamp
