Normal
end of life
The filament has grown
thinner, due to the normal evaporation of tungsten. When
this filament becomes even thinner in one section, its
fragility will make it break.
Mechanical
shock
This lamp has been subject to strong acceleration. The
sharp edges of the broken filament show this.
Over
voltage
Connecting a lamp to a tension it is not designed for
can lead to the melting of the filament
