| Se Il's quality control system consits of following quality assurance processes. |
| 1) Raw Material Incoming Inspection |
A. Filament
B. Base
C. Bulb
|
| 2) Tests on Wire-terminal Lamps |
A. Aging Test
B. Initial Charateristics Test
|
| 3) Tests on Lamps after Assembly |
A. Construction Inspection
B. Characteristics Test
C. Visual Inspection |
| 4) Test on Packing Material |
A. Pressure Test
B. Humidity-resistance Test
|
| The above processes can be summarized into the flow-chart as below : |
 |
| [ Each quality assurance process has the following specifications ] |
[ Raw Material Incoming Inspection ] |
|
|
A. Filament
|
| |
When each lot of the filament
has been produced, 50 to 100 pcs of it are made into
wire-terminal
lamps.
The filament is protected by a non-oxidizing condition,
either a vacuum or an inert gas,
inside a glass bulb.
The filament is mounted between two electrodes made
of dumet wires which provide
mechanical support and pass out
through the glass bulb for electrical connection.
Thus-made wire-terminal lamps are tested to confirm
the electrical characteristics such as voltage, current and luminosity
(M.S.C.P or lumen).
The filament has to pass the heat-resistant test as
well to see that it resists the incandescent heat and maintains the
operative condition for the duration of life-time required
by ANSI/IEC standards. The filament shape has to be uniform with coils evenly spaced and free of twist or shortening.
The filaments which are proven to be of proper quality
through such tests are used for bead-mounting or stem-mounting on
the actual production line.
|
|
B. Dumet Wire |
| |
Dumet Wire is a low resistant
material consisting of a copper sheath around a nickel-iron core.
It is given a special surface treatment permitting an
air-tight seal to be made where the electrodes pass through the
glass.
The dumet wire is visually inspected before production.
The dumet wire the copper sheath of which is peeled
off or which is wholly or partially oxidized can not used for production.
The dumet wire is carefully checked after bead-mounting
or stem-mounting for wire-terminal lamp samples to see that it does
not cause any slowly-developing air-leak on the spots where the
two electrodes pass out through the glass bulb.
|
|
C. Glass Bulb |
| |
Glass bulb is visually
inspected to see that it does not have nay deformity, crack or any
foreign material on its inner or outer surface.
Fragility is tested to see that it is strong enough
`to resist outer shock, vibration or incandescence heat.
|
|
D. Bead or Stem |
| |
Bead or stem carries one
or more piece of molybdenum wire, which are formed around the filament
to provide additional mechanical support.
Both bead and stem must have the same expansion coefficient
of the glass bulb so that any crack or deformity may not be caused
when they have been welded together at the bottom of the bulb.
|
|
[ Manufacture of wire-terminal
lamp ] |
A. When the filament, dumet wire,
glass bulb and bead (or stem)are proven to be of proper
quality through specific tests and inspections, they are used for manufacture of
wire-terminal lamps on actual production
line.
Thus-produced wire-terminal lamps
are aged for 15 to 30 minutes for initial characteristics
test
|
B. Initial characteristics Test
|
The wire-terminal lamps
which have been aged for 15 to 30 minutes are tested to check the
voltage, current, luminosity and life.
The lamp
is measured by an ampere meter to see that it stays within the tolerance
¡¾10%
at the rated voltage.
Its luminosity is tested
by a photometer to see that it has brightness within the tolerance
¡¾25% at the rated voltage.
Its life is tested at
over-voltage when it is impractical to run life tests at rated voltages.
The relationship between accelerated life values and
rated life values is generally
determined as a function of the 12th
power of voltage change
The
wire-terminal lamps which have passed the voltages, current, luminosity
and life tests
are brought to actual production line for assembly
with base by using cement. |
[ Construction Inspection ] |
A. Dimensions of the lamp are checked
to see that they meet those specified by ANSI/IEC
standards
|
B. Center of filament is checked to
see that it stays within the center 1/3 of the bulb.
|
C. Bulb has to be clear with no foreien
materials or glass chips inside.
|
D. Lamp has to be capable of operation
and storage at temperatures from -65 degrees
C to +100 degrees C without
degradation
|
E. The position of pins on midget
bayonet base and the pitch on screw base have to
meet ANSI/IEC standards.
|
F. When the lamp needs a marking on
the base, each piece of lamp is checked to ensure
a clear marking
on the base.
|
G. For a construction inspection,
sometimes a vibration test is performed on the lamp to see
that
it is not vulnerable to shock and vibration failure.
Bayonet base is recommended over screw base
where vibration exisists.
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