| 摘要 |
PURPOSE: A method for dimensionally stabilizing a tungsten filament is provided to establish a dimensional stability of a coil by removing the thermal stress of a tungsten filament before fitting to the inside of a lamp. CONSTITUTION: A method establishes coil dimensional stability of a tungsten filament(10) by thermally stress relieving the filament prior to mounting in a lamp. The filament is manipulated into the desired position by coiling it first around a primary mandrel(22), then winding the coil round a retractable secondary mandrel to form secondary coils(16). After the secondary mandrel is removed, the filament is held in place by a pair of electrical contacts(20). A current is passed through the coil, which heats the tungsten and causes it to recrystallize. The recrystallization provides the desired dimensional stability.
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