irampil@notes.cc.sunysb.edu wrote:
> I am no lighting engineer and I don't have the patience to try to
> interconvert between all the different specs for different
> lighting products. The curious thing is, just like in computing,
> these companies pick non-comparable specifications so that
> direct, rational choice is nearly impossible. I am not sure
> about comparing auto headlights and AV landing lights.
I don't think they're trying to mask comparisons, as differeing lamp specs are
based on intended application. "Candlepower" is best for spotlights or where
you're looking at the lamp, and LED's are rated that way. It's irrelevant
anyway, as for aircraft it's the approved part # as certificated. Household
light bulbs are in lumens, which says how bright the room will be as they
radiate roughly in all directions. The specs on aircraft landing lights are
irrelevant, since FAA doesn't specify brightness or beam width, and the only
relevant consideration is the approved part # as certificated for each type
aircraft.
Is confusion over wattage? I wuz confused too, but it's power consumption and
one way we buy household light bulbs due to safety considerations. But a 100W
aircraft landing light is not the same as as a 100W halogen flood lamp. The
#4509 aircraft lamp puts out enormous 110,000CP but rated at only 25 hours.
GE's catalogue for all of its halogen lamps gives you nothing like that in
equivalent wattage and beam width, but they are rated in thousands of hours.
Other posters are finding out what I have. If not using a #4509 lamp to save
some amps and installation space, the best you can do is test and find
something marginally adequate in comparison. At least you'll get long bulb
life...
Regards,
Fred F.
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