(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)):
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 |
authority: Sec. 303, Pub. L. 108-293, 118 Stat. 1042 (
33 U.S.C. 2071); Department of Homeland Security Delegation No. 0170.1
source: 79 FR 37921, July 2, 2014, unless otherwise noted.
cite as: 33 CFR 84.14