Ph!l!ps Germicidal Lamps excited by the tesla coil.

[Down with Umbrella]

[preface]
Good news, my tesla coil is up and operating again. That coil has been the Bain of my existence for the past month(s) but after some rebuilding and a substantial amount of trial & error it's working again. For now.

Anyways. Throughout My various travels I came across these tubes. To be honest I wasn't sure their purpose because they were in an unlabeled bin. After some Google searches and print inspection I found out they are mercury vapor tubes TUV Pl-l 35W
They emit visible light but also and predominantly a Ultraviolet Wave type the data sheet states as UV-C 253.7nm @ 11W.
The visible light spectrum WLs are somewhere in the 425s and 510nm with various other spikes
Pdf data sheet- http://download.p4c.philips.com/l4b/9/927904204007_na/927904204007_na_pss_aenus.pdf
Just to be safe I followed the manufacturer's safety precautions and wore a pair of gloves and my O.D 5 safety glasses when viewing. (A face shield would be better.
I doubt the coil excites the tube to full power but it's better to attempt to be safe since I have really no experience with these.

Just for the hell of it I set the tube next to some uranium marbles. That didn't quite work; if it did it wasn't noticeable with the Eagle pair safety glasses.

For those of you who don't know this tube is used as a germicide. The UV-C radiation disrupts a microorganisms Reproductive cycle by damage to the DNA.










Thanks for checking this out.
I know they're readably available but I have a total of 6 and would part with some for just a few bucks.

 

[Lifetime17]

Hi,
I have one of these tubes built onto my water system at my home i think. Mine is 4 ft.. long and kills the bacteria coming into the house system. There's a count down timer on the bulb to tell you when to replace it after 365 days these are cool So they are some where in the UV WL

Rich

 

[CoherentRays]

UV C light is not only dangerous for the eyes but it also can cause damage to the DNA of skin cells. You should protect your skin from exposure to UV C light.

Ed

 

[Benm]

Tesla coils can exite fluorescent lamps (as can radio transmitters etc), and those germicidal lamps are nothing different.

The way they generate light is exactly the same as in a tube built for domestic lighting applications, it just lacks the phosphors that convert uv light to visible, and has a quartz enclosure that allows the uv light to actually get out.

Holding them in your bare hands lit light that is a bad idea, as is looking at them without eye protection. I'd advise you to stop doing so as this can result in problems like skin cancer and cataracts quite rapidly. They may not appear that bright to the naked eye, but emit more power that the equivalent sized lighting tube, most of it as invisible uv light.

I see you are using a glove in later pictures which is good as far as skin cancer risk goes, but still do not look into them, and beware that even the apparently dim output can seriously damage exposed skin further away... and these are UV-C lights, which do not give you a nice tan, only sunburn-like problems.

 

[Sigurthr]

Good to see that coil up and running again!

Yep it'l light up just about anything with a rarified gas in it.

254nm doesn't fluoresce many materials into the visible light spectrum, and the visible wavelengths from the Hg swamp out your vision so you don't see the fluorescence anyway.

 

[Down with Umbrella]

All excellent suggestions and feedback. other than that first shot holding the tube there was minimal exposed skin. I'm not even sure the eagle pair glasses were safe as a face shield would provide optimum protection. The visible color is pretty cool. The low 500s is my favorite WL. Not the mid 250s though:$

Lifetime17, did you say there was a timer somewhere? These are probably expired

 

[Cyparagon]

I'm not even sure the eagle pair glasses were safe as a face shield would provide optimum protection.

They do. Just about everything blocks UVC. Regular sunglasses, eyeglasses, or polycarbonate safety glasses would also be fine.

 

[Down with Umbrella]

Oh, I was referring to area coverage. The eagle pair would protect my eyes but a faceshield world cover my face better from exposure.
Too bad sunscreen didn't come with a UV-C protection. :crackup:

Anyways these tubes will be benched.

 

[Benm]

Yeah, protection from 254 nm is not hard to get for your eyes, the average pair of sunglasses sold by a beach bum for $5 would do just fine.

But as pointed out this light is also quite dangerous to the skin, so you would want protection to cover more than your eyes. A face shield would help, and need not to be made of any special material - standard impact resistant plastics like polycarbonate completely block this wavelength.

I'm not sure how brighty they light under a tesla coil, but when powered from their proper ballasts these lamps will give you a pretty nasty skin burn in minutes at a feets distance or so.

 

[paul1598419]

UV-C is highly ionizing radiation and it the main reason we have a protective O3 layer in the upper atmosphere.

 

[Benm]

I think that's the other way around - we have no protection mechanism against UVC because it was never an issue during our evolution. Damaging that ozone layer was a bit of a mishap on our part, but i guess we mostly stopped doing so some time ago.

Bacteria also never needed to develop a coping mechanism, which is why these lamps are germicidal in the first place. Then again bacterial generation intervals are so small they could actually learn to cope with it much faster than we can

 

[Down with Umbrella]

So what you're saying is UV-C radiation probably wouldn't kill a vampire? Heh
Interesting perspective that bacteria never evolved a defense against it.
Two questions: 1)what aspect of UV-C makes it more harmful than A&B? Apart from a higher energy density.
2) why wouldn't the tube's UV-C excite the Uranium in the marbles? Is that wavelength too short or the marbles only glow in a certain Window of ultraviolet radiation?

 

[Cyparagon]

DNA has high absorption at UVC. Damaging DNA is a nono, for reasons I'm sure you're aware of.

UVC would probably be stopped by the glass before it got to much of the uranium in the first place. These lamps also emit UVA at 365nm. That would cause the marble to glow.

 

[paul1598419]

DNA has high absorption at UVC. Damaging DNA is a nono, for reasons I'm sure you're aware of.

UVC would probably be stopped by the glass before it got to much of the uranium in the first place. These lamps also emit UVA at 365nm. That would cause the marble to glow.

This^. The reason you can't see the fluorescence is because the visible light is so great it washes out any fluorescence. If you could somehow block all the visible light while allowing the UV to escape, you would see the fluorescence.

 

[Benm]

DNA is also damaged by UVA and UVB really, which do reach the ground, and which we have protection mechanisms against such as tanning, and permanently pigmented skin for those that evolved in more sunny regions where there was never a lack of uv light required for the synthesis of D-vitamins.

As for fluorescence from 254 nm light: it's not spectacular or anything. Most things that do fluoresce do so by excitation from longer wavelength lines. These lamps really arent all that visible to begin with nor do they cauase madly bright fluorescence in other materials. This makes them quite dangerous actually as they are swamped out by visible light sources and hence could be overlooked when accidentily turned on.

Flow cabinets that use them for sterilization usually have a mechansim that turns them off if you raise the glass door high enough to do any work in them, probably for good reason.

 

[Down with Umbrella]

Thanks for the input. It was mentioned earlier above in the thread about visible light swamping out fluorescence but I guess it didn't click until now.

Does anyone have and sources of other gas tubes? I have one xenon tube, a common incandescent bulb(argon)
I'd like to find some other Nobel gases but anything on eBay are fairly small ampoules. (45-50mm)

Thoughts?