Re: LIghts Question

["Frank Amoroso" <famoroso@sprintmail.com>]

Date: Tuesday, January 13, 1998 12:56 AM
Subject: LIghts Question


>
>Thanks for posting that very informative summary to the q-list.  I'm still
>confused though :)
>
>I looked up Wagner Lighting (www.cooperauto.com), and they have a "Brite
>Lite" bulb that they claim is Xenon, but in there FAQ, they say HID is
>different from Xenon:
>http://www.cooperauto.com/frames/aftermkt/wagner/faq.html
>
>In your explanation, you classed them together.  I also looked up Hella,
>and it looks like they have direct replacement Xenon bulbs
>http://www.hella.co.nz/xenon.htm
>
>So, how do HID and Xenon differ?  Does HIDs use Xenon bulbs?  If my car
>can take H4s (I haven't checked -- it's an A4), can I just pop in Hella
>Xenon H4s and I'll end up with brighter, "bluer" light?
>
We run into a bit of a problem with nomenclature here as the Wagner & Hella
bulbs you refer to are just that "bulbs." If you recall from my original
post the Xenon capsule (the "bulb" in a HID sytem) does not have a filament,
but rather a gap between two conductors, in a capsule filled with Xenon (and
other inert Noble gasses, depending in the manufacturer). An extremely high
voltage charge (along the lines of 28,000 volts) is applied to the
conductors and the ensuing arc provides the luminosity.

The wagner & hella products are enhanced halogen bulbs. And all you need to
do is have +12 volts on hand and the bulb will emit light. How much good it
does and how much marketing hype it is, is debatable. The claim is that
compared to a standard halogen bulb, the Xenon enhanced units run coller and
more effeciently. Claim: 85 watts of luminosity from a 55 watt bulb.  I'm
not sure, as I have yet to test them for myself, but a write up was done
several quattro quarterly's ago that said they were not worth the extra
cost. The only true way to measure or compare the light output is in lumens.
A lumen is the most meaningful measure of a light's "power". A lumen is a
unit of measurement for the total amount of light a lamp produces, including
both the focused and wide angle portions of the beam. Total light is best
measured using an instrument called an "integrating sphere," and given in
lumens. The lumen is a much better unit of measure for comparison purposes
than "candlepower" , since candlepower, as commonly used, is merely a
measure of the intensity of the hottest spot in the beam. So short of buying
an integrating sphere and testing the light output of standard halogen
versus the enhanced halogens you are left to fly by the seat of your
eyeballs.


                Frank--