Table 4-6.--Description of Mogul Lamps
FLUORESCENT LAMPS
Table 4-6 describes lamps with bases classified as
Mogul (fig. 4-7).
The fluorescent lamp is an electric discharge lamp
that consists of an elongated tubular bulb with an
Characteristics
oxide-coated filament sealed in each end to comprise
The average life of standard incandescent lamps for
two electrodes (fig. 4-8). The bulb contains a drop of
general lighting service, when operated at rated voltage,
mercury and a small amount of argon gas. The inside
is 750 hours for some sizes and 1,000 hours for others.
surface of the bulb is coated with a fluorescent phosphor.
The light output, life, and electrical characteristics of a
The lamp produces invisible, short-wave (ultraviolet)
lamp are materially affected when it is operated at other
radiation by the discharge through the mercury vapor in
than the design voltage. Operating a lamp at less than
the bulb. The phosphor absorbs the invisible radiant
rated voltage will prolong the life of the lamp and
energy and reradiates it over a band of wavelengths to
decrease the light output. Conversely, operating a lamp
which the eye is sensitive.
at higher than the rated voltage will shorten the life and
NOTE: black dot inside a lamp symbol designates
increase the light output. Lamps should be operated as
a gas-filled tube. (See fig. 4-8, views A and B.)
closely as possible to their rated voltage.
Because of their low efficiency, incandescent lamps
Fluorescent lamps are now used for the majority of
are used less frequently as light sources for interior
both red and white lighting on naval ships. For lighting
lighting on naval ships.
fixtures that can be seen external to the ship by another
Figure 4-7.--Lamp sockets.
4-8
