[sci.electronics] krypton .vs. halogen, which is better?

billp@col.hp.com (Bill Pherigo) (04/19/91)

     What is the performance difference between halogen "flash light type"
bulbs and krypton bulbs.  They both seem to use the same amount of power, but
the halogen cost about 5 times as much as the krypton.  I understand that the
halogen stays the same brightness throughout its life.  Is this true for the
krypton?  I also have heard that the halogen won't last long if not run very
close to it's specified voltage.  Does the halogen put out more light for the
same input power?  Is one more sensitive to mechanical vibration than the other?

Bill Pherigo
<billp@col.hp.com>
(719) 590-3420

paull@hplred.HP.COM (Robert Paull) (04/25/91)

  That's funny, I thought that Neon,Argon,Krypton and Xenon WERE
halogens? Was my chen teach' wrong???


RP

whit@milton.u.washington.edu (John Whitmore) (04/25/91)

In article <38610009@col.hp.com> billp@col.hp.com (Bill Pherigo) writes:

>     What is the performance difference between halogen "flash light type"
>bulbs and krypton bulbs.  They both seem to use the same amount of power, but
>the halogen cost about 5 times as much as the krypton. 

	Standard flashlight bulbs are vacuum type, and are VERY efficient.
Their average lifetime is 9 hours.  Halogen bulbs last longer (2000 hours
is typical in home use), but run hotter (lose energy by heat conduction),
so could be presumed to be less efficient.  That presumption would be
incorrect, however, since there's a second difference: the halogen
bulbs run a higher filament temperature, and give off much whiter
light than vacuum bulbs.  Krypton bulbs similarly run a higher
filament temperature, but will not last as long (perhaps 100 hours,
however, a LOT longer than the vacuum bulbs).

	For my bike light, I purchased all three types of bulbs,
and tested them for light output and color.  The Krypton and halogen
bulbs both had much bluer output (vital for night vision; your eye's
rods are insensitive to red light) than the vacuum bulb.  The Krypton
bulb used more power than the halogen I used, and was accordingly
brighter (as well as more energy-efficient) than the halogen.

	And I ended up using the halogen, because it is probably more
reliable.

	John Whitmore

larry@kitty.UUCP (Larry Lippman) (04/26/91)

In article <1270004@hplred.HP.COM> paull@hplred.HP.COM (Robert Paull) writes:
>  That's funny, I thought that Neon,Argon,Krypton and Xenon WERE
>halogens? Was my chem teach' wrong???

	I suppose one could say that Neon, Argon, Krypton and Xenon WERE
halogens until someone added an electron (and proton and neutron) to make
them the INERT GASES that they are.

	:-)

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
VOICE: 716/688-1231       {boulder, rutgers, watmath}!ub!kitty!larry
FAX:   716/741-9635   [note: ub=acsu.buffalo.edu] uunet!/      \aerion!larry

paull@hplred.HP.COM (Robert Paull) (04/26/91)

Oops, I guess I was wrong about the Halogen gases. I humbly apologize.
A mind is a terrible thing..   ;-)

RP

ardai@teda.Teradyne.COM (Mike Ardai) (04/29/91)

In article <1270004@hplred.HP.COM> paull@hplred.HP.COM (Robert Paull) writes:
>  That's funny, I thought that Neon,Argon,Krypton and Xenon WERE
>halogens? Was my chen teach' wrong???

Someone was...

Halogens: Flourine, Chlorine, Iodine, Bromine, Astatine
Noble (Inert) Gasses: Helium, Neon, Argon, Krypton, Xenon, Radon

/mike
-- 
\|/  Michael L. Ardai N1IST   Teradyne EDA East
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