BS 8442:2006 pdf download.Miscellaneous road traffic signs and devices -Requirements and test methods.
13.2.2.2 Mean luminance and uniformity of luminance
When nwasured as described in 13.2.2.3, the mean luminance of the globe shall be not less than 300 cdin The uniformity of luminance, in terms of the ratio of the mimmuin to the maxinwm measured luminance of the globe, shall be not less than 0.66.
13.2.2.3 Measurement of mean luminance and uniformity of luminance
Measurements shall be made in accordance with BS EN 13032-1.
The beacon globe shall be illuminated using the light source with which the globe is to be used, mounted in the position in which it is to be when the globe is in use.
Measurements shall be taken in a direction normal to the tangent to the surface of the globe at the points shown in Figure I on an area of the globe of (25 ± 0.5) mm projected diameter.
The measurements shall be repeated at angles of 1200 and 240° in plan to the original direction.
The mean luminance and uniformity of luminance shall be calculated in accordance with BS EN 13032-1.
13.2.2.4 Visibility of light source
When the globe is illuminated, the light source shall not be visible through the globe material.
When nwasured as described in 13.2.2.3, the mean luminance of the globe shall be not less than 300 cdin The uniformity of luminance, in terms of the ratio of the mimmuin to the maxinwm measured luminance of the globe, shall be not less than 0.66.
13.2.2.3 Measurement of mean luminance and uniformity of luminance
Measurements shall be made in accordance with BS EN 13032-1.
The beacon globe shall be illuminated using the light source with which the globe is to be used, mounted in the position in which it is to be when the globe is in use.
Measurements shall be taken in a direction normal to the tangent to the surface of the globe at the points shown in Figure I on an area of the globe of (25 ± 0.5) mm projected diameter.
The measurements shall be repeated at angles of 1200 and 240° in plan to the original direction.
The mean luminance and uniformity of luminance shall be calculated in accordance with BS EN 13032-1.
13.2.2.4 Visibility of light source
When the globe is illuminated, the light source shall not be visible through the globe material.
