5.2.1 By day and with an atmospheric transmission
of 0.8, the visibility of light signals emitted by daylight signalling
lamps should be at least 2 nautical miles, equalling a required luminous
intensity of 60,000 cd.
5.2.2 The axial luminous intensity of daylight
signalling lamps should reach at least 90% of the maximum luminous
intensity.
5.2.3 The luminous intensity of daylight signalling
lamps should have its maximum in the centre of the luminous intensity
distribution. It should decrease evenly from the centre of luminous
intensity distribution.
5.2.4 The half angle of divergence ah should
not exceed 9°, the tenth angle of divergence az should
not exceed 14°.
5.2.5 The chromaticity of the white signal light
should lie within the following corner co-ordinates of the diagram
specified by the International Commission on Illumination (CIE) in
CIE Publication No. 2.2:
x
|
0.525
|
0.525
|
0.452
|
0.310
|
0.310
|
0.443
|
y
|
0.382
|
0.440
|
0.440
|
0.348
|
0.283
|
0.382
|
5.2.6 The effective light emission sectors of
daylight signalling lamps should be circular. The sum of switch-on
and switch-off times should not exceed 500 ms.