6. LUMINANCE.
Luminance is defined as the luminous intensity per unit area of an extended
light source.
The unit of luminance used for photoluminescent materials and products
is the millicandela/m2 (mcd/m2).
6.1. LUMINANCE DECAY TIME.
This is the time required for the luminance to decay to specified levels
of luminance following the complete withdrawal, or loss, of an activating
illuminating light source.
6.2. ILLUMINANCE.
Illuminance is the luminous flux density at a surface, i.e the luminous
flux incident per unit area. The unit of illuminance is the lux.
6.3. LUMINANCE CLASS I PHOTOLUMINESCENT
MATERIAL.
A photoluminescent material tested according to DIN 67510 Part 1 1992
and giving luminance values versus decay times in the range as follows:
|
Time period |
10 mins |
30 mins |
60 mins |
>240 mins |
|
|
||||
|
Luminance |
||||
|
mcd/m2 |
>17.0 |
4.0 |
1.7 |
0.3 |
|
|
||||
6.4. LUMINANCE CLASS II PHOTOLUMINESCENT
MATERIAL.
A photoluminescent material tested according to DIN 67510 Part 1 1992
and giving luminance values versus decay times in the range as follows:
|
Time period |
10 mins |
30 mins |
60 mins |
170-240 mins |
|
|
||||
|
Luminance |
<17.0 |
4.0 |
1.7 |
0.3 |
|
mcd/m2 |
>12.5 |
2.9 |
1.2 |
0.3 |
|
|
||||
6.5. LUMINANCE CLASS III PHOTOLUMINESCENT
MATERIAL.
A photoluminescent material tested according to DIN 67510 Part 1 1992
and giving luminance values versus decay times in the range as follows:
|
Time period |
10 mins |
30 mins |
60 mins |
80-160 mins |
|
|
||||
|
Luminance |
<12.0 | 2.8 | 1.1 | 0.3 |
|
mcd/m2 |
> 8.5 | 1.5 | 0.5 | 0.3 |
|
|
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