User Guide

For more complete product information visit www.sylvania.com Symbols/Footnotes on page 160-165
129
OSRAM SYLVANIA: THE LEADER IN
ENERGY SAVING FLUORESCENT LAMPS
The fluorescent lamp is an electric discharge device which utilizes a low pressure mercury vapor arc to generate ultra-violet
(plus a little visible) energy. The ultra-violet energy is absorbed by a phosphor coat on the inside of the glass tube
and converted by the phosphor to visible wavelengths; the wavelengths of the light generated are determined by the
composition of the phosphor. In addition to the small amount of mercury vapor, the fluorescent tube contains an
atmosphere of an inert gas, usually argon, krypton, neon, or a mixture of two or more of these gases. The pressure
of the gases contained in the lamp is very low, usually from 2 to 3 torr. Atmospheric pressure is 760 torr.
F
L
U
O
R
E
S
C
E
N
T
Usually straight glass tube.
May also be circular or U-
shaped.
Several different types
used to connect the
lamp to the electric cir-
cuit and to support the
lamp in the lampholder.
Connect to the base pins
and carry the current to
and from the cathodes
and the mercury arc.
The lead-in wires have
an air tight seal here
and are made of specif-
ic wire to assure about
the same coefficient of
expansion as the glass.
Usually argon or a mix-
ture of inert gases at
low pressure. Krypton
is sometimes used.
A minute quantity of
liquid mercury is
placed in the bulb to
furnish mercury vapor.
Air is exhausted
through this tube dur-
ing manufacture and
inert gas introduced
into the bulb.
“Hot cathodes” at each end
of lamp are coated with
emissive materials which
emit electrons. Usually
made of coiled-coil or single-
coil tungsten wire.
Coating inside the bulb
transforms ultraviolet radi-
ation into visible light.
Color of light produced
depends on composition
of phosphor.
BULB
BASE MERCURY
GAS
STEM PRESS LEAD-IN WIRES
EXHAUST TUBE
PHOSPHOR
CATHODE
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