GrnXnham said:
winny
That is a good thread. Thanks
Dave
I have since learned of a slight correction to my understanding of xenon and halogen lamps, and it is this:
A pure high pressure xenon lamp is actually more efficient than one with a trace amount of a halogen added (such as bromine or iodine), because you must lower the pressure somewhat if you add a halogen to the mix, otherwise the halogen will attack the filament and corrode it. This explains why a company (such as Carley Lamps) would offer a xenon non-halogen lamp that blackens over time--because it is brighter to start with, for the same power.
However, you can compromise between the two and add enough halogen to slow down the blackening due to tungsten deposition on the glass, but not enough to prevent it entirely. Thus you get a lamp that, on average, is the highest efficiency an incan lamp can be, all other factors being equal.
The SureFire MA02 lamp for the SF A2 is an example of such a xenon lamp that is sort-of a halogen.
In any case, if a lamp has a xenon fill gas, halogen or not, the manufacturers will advertise it as such, and don't bother to go into whether or not it is a halogen, and to what degree.
The Welch Allyn lamps, on the other hand, are full halogens and do not blacken over their life. But, IIRC, they use krypton as the main ingredient in the fill gas.
The Osram 62138 HLX is a full halogen lamp with xenon fill gas, and goes by the moniker "Xenophot". Any "HLX" Osram lamp is a xenophot as far as I can tell, although I am not positive about that.
Anyway, there it is. Correct info as far as I know.
