They are further classified according to use, such as
alters the characteristics of the light emitted by the lamp.
A clear glass globe (fig. 4-12, view B) absorbs a small
regular permanent white-light fixtures,
percentage of the light without appreciably changing the
regular permanent red- or yellow-fixtures,
distribution of the light. A diffusing glass globe absorbs
a little more light and tends to smooth out variations in
portable fixtures,
the spherical distribution of the light; whereas, a
miscellaneous fixtures,
colored-glass or plastic globe absorbs a high percentage
of the light emitted by the lamp. A baffle conceals the
navigation lights, and
lamp and reduces glare. A reflector intercepts the light
traveling in a direction in which it is not needed and
lights for night-flight operations.
reflects it in a direction in which it will be more useful.
Regular permanent white-light fixtures
CLASSIFICATION OF FIXTURES
(incandescent, fig. 4-12, views A and B, fluorescent, fig.
4-12, views C and D) are permanently installed to
Lighting fixtures are classified according to the type
provide general illumination and such detail
of enclosure provided, such as
illumination as may be required in specific locations.
General illumination is based on the light intensity
watertight,
required for the performance of routine duties. Detail
nonwatertight,
illumination is provided where the general illumination
is inadequate for the performance of specific tasks.
pressure-proof, or
Sources include berth fixtures, desk lamps, and plotting
lamps.
explosionproof.
Figure 4-13.--Weatherdeck floodlights.
4-14