Table A
Requirements for Shielding and Filtering
| |||
---|---|---|---|
Fixture Lamp Type
|
Shielded
|
Filtered4
| |
Low-pressure sodium1
|
Partially
|
None
| |
High-pressure sodium
|
Fully
|
None
| |
Metal halide6
|
Fully
|
Yes
| |
Fluorescent
|
Fully5
|
Yes2
| |
Quartz3
|
Fully
|
None
| |
Incandescent (greater than 150 watts)
|
Fully
|
None
| |
Mercury vapor
|
Fully
|
Yes
| |
Fossil fuel
|
None
|
None
| |
Glass tubes filled with neon, argon, krypton
|
None
|
None
| |
Other sources
|
As approved by planning staff
|
NOTES:
| ||
---|---|---|
1
|
The preferred light source to minimize undesirable light into
the night sky affecting astronomical observations.
| |
2
|
Warm white and natural lamps are preferred to minimize adverse
effects.
| |
3
|
For the purposes of this article, quartz lamps shall not be
considered an incandescent light source.
| |
4
|
Most glass, acrylic, or translucent enclosures satisfy these
filter requirements.
| |
5
|
Outdoor advertising signs of the type constructed of translucent
materials and wholly illuminated from within; do not require shielding.
| |
6
|
Metal halide display lighting shall not be used for security
lighting after 11:00 p.m. (or after closing hours if before 11:00
p.m.) unless fully shielded; metal halide lamps shall be in enclosed
luminaries.
|