Film-Tech Forum ARCHIVE: How to make a xenon lamp.

This is topic How to make a xenon lamp. in forum Film-Yak at Film-Tech Forum ARCHIVE.

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Posted by Stephen Furley (Member # 1277) on 04-18-2013, 06:16 AM:

We used to have a member who worked at a company that made xenon lamps. I haven't seen any posts from him for a long time, but maybe somebody else knows the answer to this.

Apart from the high temperature required to work quartz, blowing the bulb for a xenon lamp wouldn't be particularly difficult. Sealing the electrodes into the quartz is a different matter, but I have a rough idea how it is done. What I don't understand is this; I've done a bit of work with low-pressure lamps, I'm actually going on a neon sign course tomorrow. Sealing off these lamps is easy, you just heat the exhaust tubulation with a gas torch and as the glass softens it sucks in under the near vacuum inside, and seals off the lamp. However, this obviously isn't going to work with a lamp which is significantly above atmospheric pressure even at room temperature. So, how do you seal off a xenon lamp? Do they put the whole lamp inside some sort of container at a higher pressure than that inside it or something?

Posted by Jim Cassedy (Member # 4115) on 04-18-2013, 09:40 AM:

One of the major xenon lamp manufacturers used to have a 'white paper'
posted online that detiled EVERYTHING you ever wanted to know about
xenon lamps. (Even how & where they got the xenon gas from!)

I just searched online to see if I could find it again, with no luck.

I have a PDF copy on my other computerthingy, which is unfortunately
in the shop at the moment, recovering from a really bad virus attack.

Maybe when I get it back I can e-mail you a copy and/or post it in the
warehouse section if you don't get the answer you're seeking from
someone else here.

(assuming the virus hasn't wiped out my wholefriggin' hard drive!)

Posted by Joe Elliott (Member # 4006) on 04-18-2013, 09:51 AM:

Found the answer in the osram bulb technical paper, although I don't know if it answers your question totally.

quote:
Depending on lamp design, cold XBO
®
lamps are filled to a
pressure between 5 and 15
bar.
In order to obtain this positive
pressure in the lamps, the
xenon is frozen into the lamp body
during manufacture. The
pressure in the lamp rises during operation to about four times the
value because of the
temperature.

Osram bulbs

quote:
Depending on lamp design, cold XBO
®
lamps are filled to a
pressure between 5 and 15
bar.
In order to obtain this positive
pressure in the lamps, the
xenon is frozen into the lamp body
during manufacture. The
pressure in the lamp rises during operation to about four times the
value because of the
temperature.

Posted by Jim Cassedy (Member # 4115) on 04-18-2013, 10:25 AM:

That (freezing) makes a lot of sense. After I wrote my post I
also considered the possibility that the entire final stages of
manuafacturing the bulb took place in some sort of
a pressurized environment.

Posted by Carsten Kurz (Member # 5396) on 04-18-2013, 10:42 AM:

The free online publication of CinemaTechnologyMagazine had lab reports from Philips/LTI and OSRAM in past editions (18 and 20) - lot's of information regarding specific manufacturing issues, history, photos, etc.

After you read both articles, you understand that

- xenon bulbs are still delicate to make
- manufacturers basically have options to either utilize a high degree of automation/machinery, or a very well trained staff with a high amount of manual work. Both methods have their pro's and con's.

One statement from a european USHIO representative once was, that USHIO also uses a lot of manual work with very specific and long time trained knowledge on their bulbs.

Knowing this may also explain why some manufacturers sometimes have higher failure-rates or why changes in the manufacturing logistics can have such a high impact on product quality.

Xenon manufacturing obviously has no place for hire&fire staffing policy.

http://emag.cinematechnologymagazine.com/

http://emag.cinematechnologymagazine.com/Index.aspx?issue=issue20

http://emag.cinematechnologymagazine.com/Index.aspx?issue=issue18

(I know it's one of these strange online readers, but registration is free, painless, no spam, no issues, and reading is always very interesting)

- Carsten

Posted by Louis Bornwasser (Member # 3063) on 04-18-2013, 02:02 PM:

I watched this in Germany. Put the bulb in liquid hydrogen; put the large syringe of liquid xenon in liquid hydrogen. Quickly load the liquid xenon in the fill tube and quickly seal. Put the plastic explosion shield around bulb and allow to warm up to room temperature. This is all the presserization that is needed. Volume of xenon liquid and internal area of bulb determine bulb pressure at room temperature.

Liquid xenon is greyish brown in color and it lays there in the bottom of the bulb until it turns gaseous. Louis

Posted by James Wallor (Member # 6154) on 04-19-2013, 10:49 AM:

This sounds like it'd be a really cool process to see. I had no idea these bulbs were so difficult to make.

Posted by Jeffry L. Johnson (Member # 453) on 04-20-2013, 02:18 PM:

Liquid nitrogen?

Posted by Richard Fowler (Member # 893) on 04-20-2013, 05:15 PM:

I remember a tour of the old ORC facility with much hand finishing of bulbs with custom jig tools. Defective (failing factory tests) bulbs where salvaged to save end terminals and recycled if there where in spec. The reflector division with ORC reflectors and clients such as Maglight flashlight reflectors being created by large vats of electro-plating machinery......

Posted by Richard Fowler (Member # 893) on 04-20-2013, 05:16 PM:

I remember a tour of the old ORC facility with much hand finishing of bulbs with custom jig tools. Defective (failing factory tests) bulbs where salvaged to save end terminals and recycled if there where in spec. The reflector divsion with ORC reflectors and clients such as Maglight flashlight reflectors being created by large vats of electro-plating machinery......