Building a Simple UV Lamp

Sounds like you're looking for a germicidal mercury lamp...

They are the sort used in UV EPROM erasing machines, basically a mercury discharge tube which emits light at around 273nm although the tubes for general use do emit light at other frequencies as well due to impurities, that's why they appear to the naked eye as a purple / blue light source...

Dangerous to view though for the same reasons as getting 'arc-eye' and skin cancer etc...

For true single line output you will need to get hold of a specialist supplier of scientific equipment, they can supply tubes which emit at one wavelength such as sodium etc...

John.

Thanks Electroman, but I was thinking of building the uv lamp myself as a hobby/personal project. So, it would be great if the materials can be found at an average electronic/hardware shop (and at minimum costs of course :) ).

But thanks anyway, ermm.. do you think there'll be any uv bulbs that can be found in surgical or electronic shops? Thanks again fro the reply.

I assume you mean you are wanting to build a lamp, as in an assembled light source?

Not to actually build a light bulb?!!

Its the bulb that's the important bit, if you want a single line output you will need a specialised bulb from a scientific supply company, and they will be costly.

John.

Oh I see, and yes I want to build a lamp. But I am just wondering if it is possible if we can use a normal bulb (halogen/mecurial/etc.) and use a filter to specialise the wavelength?

You want to build a fixture for a UV lamp.

The fixture may come into plan some time later. But right now I am more interested in building a hand-held uv lamp.

But you brought up a great idea. Maybe I'll buy some photodiode and build the fixture around it, making myself a nice spectrometer.

But first lets concentrate on the lamp first shall we. From the net I found out the a normal blacklight bulb is made in the same fashion as a normal fluorescent lamp only fitted with a special glass called wood's glass. Even incandescent bulb or mercury vapor can be use. But I'll avoid these on terms of safety.

I tried asking around my hardware stores for these blacklight/wood's glass bulb but to no avail. Perhaps, I'm missing something or using the wrong term.

GE supply used to have germicidal lamps in various sizes. They had a small one about 6 inches long that folded back on itself that was a handy size for an EPROM eraser. They work just like normal fluorescent lamps and you can use simple ballast and a push button to start it. You could also power it with a solid-state inverter to create a current limited high voltage. You might use it as a source if it has the spectral line of interest and check Edmund Scientific or other suppliers of optical components for a narrow spectrum filter that may meet your requirements.

I bought a hand-held UV light that ran on batteries. It gave off two frequencies - an upper and a lower from the same bulb. It accomplished this by two filters mounted in front of the lamp housing. The spectrum of most lamps is pretty wide, after all, it's basically black-body radiation. Only a part of the lamps spectrum was in the UV.

Anyway the filters gave very precise frequencies. The lamp was sold for checking the UV stamp they put on the back of your hand to let you go out and back into night clubs, however, it could really light up a darkened room. Surprising how many things Flores at these frequencies! I think it cost less than $50.00.

Ever thought about UV - LED's ?

That works, too.

The point is, Cloud8521, you don't need to get into high power, high voltage lamps. For experiments with fluorescents, there are handy, lower power, and safer options on the market. Just look around.

There is a sigificant different between the germicidal lamps you are discussing and the black light. A germicidal lamp has no fluorescent coating inside it. I directly emits the UV light made by the excited mercury vapor inside the lamp. The glass is different than the glass in a standard fluorescent lamp in that it allows the UV in the C, B, and some times in the A spectrum to pass through it. This kind of lamp is used for many purposes, from suntan lamps at your tanning bed to product testing laboratories that use them to test the effect of UV exposure on most any product exposed to sunlight for long periods of time ie: paint, plastics, and as germicidal agents for sterilization of water and medical instruments.

A black light uses a fluorescent coating inside the lamp that does not produce UV in the A and B ranges these are the most harmful, and the intensity of the light is greatly reduced making them much safer for use. They can be purchased at novelty shops to illuminate posters and if you watch "CSI type shows on TV they are used to illuminate the florescent dyes used to detect blood at crime scenes.

Regards Mike

What is the purpose of this UV luminaire?

If you just want this for the project- considor using an UV LED. they are available for a few dollars. The entire project should cost under $10. If You need more brightness you can always use multiple LEDs. LED's won't put you into the below 370 wavelength.

You can also use CCFT lamps that require an inverter. Here is a link for one:

http://www.allelectronics.com/cgi-bin/item/FL-4UV/search/4%22#34;CCFT_LAMP,_UV_BLACK_LIGHT_.html

These can hurt your eyes.

Rbeadle

The lamp is for a little project I have. It will mostly be used in illuminating organic fluids, what's in them i.e. checking bacterial growth, etc. but mostly it will be for recreational discovery/research use.

I've got to reiterate what another post already mentioned: USE appropriate EYE PROTECTION! This applies to all who are even near your light source, not only those who are watching!

Once while teaching science I used a portable mineralight to illustrate fluorescence to several classes the same day. I thought I was keeping the lamp pointed away from my face and therefore would be safe, but I clearly got enough direct and/or reflected UV to burn my eyes. It felt like my eyes were full of sand - the most painfull thing I've ever felt!

Have Careful Fun!

Dick

You can use LED's or mount your light source in a light proof box and use fibre opticts to get the light to the work area. Use special goggles to filter out the UV. There are two main types UV "A" and "B" be aware that it is not only your eyes at risk you can cause sever burns to you skin. And provoke lethal skin cancers to add to you list of dangers.

Seriously, getting the type of lamp you want is no big deal! Try checking Edmund Scientific or The Discovery Store. There is a bunch of them out there that don't involve working with power supplies, costly mercury vapor lamps, da, da, da.

But as everyone else has told you, even if the thing seems like a fun toy, just be careful of your eyes.

These are pretty cool, will disinfect water for whole house...Don't know the exact wavelength, but you could call...

http://rowatersystems.com/Catalog/sq-pa_sterilight__r-can__uv_system_4277320.htm

This may be more what you want, portable, battery powered, 365nm wavelength, and cheap!...

http://www.solarstop.net/edtm/1_lamps_light_sources.htm?1

This has to be the best deal, combo uv pen and light, $20...tooo cool

http://www.pimall.com/nais/e.smark.html

SolarEagel is right! And he's only scratched the surface. Just do a little Googling, they're out there.

Here are a couple of interesting Wikipedia links that may help shed some light on the subject (no pun intended): http://en.wikipedia.org/wiki/Ultraviolet and http://en.wikipedia.org/wiki/Woods_glass .

Cloud8521-Just Google 'ultraviolet radiation' and you will find quite a few sites on the subject.