Title 33
SECTION 84.14
84.14 Intensity of lights.
§ 84.14 Intensity of lights.(a) The minimum luminous intensity of lights shall be calculated by using the formula:
I = 3.43 × 10 6 × T × D 2 × K−D Where: I is luminous intensity in candelas under service conditions, T is threshold factor 2 × 10−7lux, D is range of visibility (luminous range) of the light in nautical miles, K is atmospheric transmissivity. For prescribed lights the value of K shall be 0.8, corresponding to a meteorological visibility of approximately 13 nautical miles.(b) A selection of figures derived from the formula is given in the following table (Table 84.14(b)):
Table 84.14(b)
Range of visibility (luminous range) of light in nautical miles D |
Minimum luminous intensity of light in candelas for K = 0.8 I |
---|---|
1 | 0.9 |
2 | 4.3 |
3 | 12 |
4 | 27 |
5 | 52 |
6 | 94 |