Measurement methods. 1.1. When photometric measurements are taken, stray reflections shall be avoided by appropriate masking. 1.2. In the event that the results of measurements are challenged, measurements shall be taken in such a way as to meet the following requirements: 1.2.1. the distance of measurement shall be such that the law of the inverse of the square of the distance is applicable; 1.2.2. the measuring equipment shall be such that the angle subtended by the receiver from the reference centre of the light is between 10' and 1°; 1.2.3. the intensity requirement for a particular direction of observation shall be satisfied if the required intensity is obtained in a direction deviating by not more than one quarter of a degree from the direction of observation. 1.3. In the case where the device may be installed on the vehicle in more than one or in a field of different positions the photometric measurements shall be repeated for each position or for the extreme positions in the field of reference axis specified by the manufacturer. Annex 3
Appears in 3 contracts
Sources: Agreement Concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Agreement Concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Agreement Concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles