Re: alfa-digest V7 #133

[GLewis4457@xxxxxxx]

In a message dated 9/26/98 4:00:00 AM Central Daylight Time, owner-alfa-
digest@domain.elided writes:

> The lamp test that they were likely referring to is checking the filament
>  inside the bulb. When the filament is hot (i.e. the lamp is "on"), it is 
> much
>  more fragile than when cold and will break easier. If the filament in an
>  otherwise undamaged bulb is broken, the lamp was likely "on" at the moment 
> of
>  impact. 
Gary;

It is my understanding that a bulb that burns out normally in the controlled
nitrogen atmosphere of the bulb will have one set of chemical characteristics.
When the bulb breaks and the bulb is lit, as it would be in a braking
situationl, the hot filament is exposed to the air and "carbons up" as it
burns out exposed to the oxygen rich atmosphere.  This leaves a tell tale
layer of carbon over the surface of the filament.  I don't know whether the
filament actually gets hot enough to melt.

Jerry in Houston

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