I've been searching for reasonably priced spectrum discharge tubes as element samples.
Did anyone had some experience with purchasing/using those?
The prices I've seen on ebay were about 22$ for a tube.
Although I've stumbled upon some Indian companies that sell them for 6-7$ a piece, has anyone had any experience with them? Or they only sell to
companies and not individuals?Mixell - 29-5-2012 at 02:49
I've contacted the Indian supplier, and I will probably order some.
Is anyone else interested?
The tubes are 26cm long, with capillary tube of 10cm length and are fitted with nickel electrodes, they are filled with the following gases:
If anyone is interested, leave me a U2U. Endimion17 - 29-5-2012 at 06:43
Would it be cheaper to order them from people that make neon signs? They probably wouldn't/couldn't make all of these, and their gasses probably
aren't extremely pure, but that's a start... I seriously doubt these 15$ tubes from India are much different.
If you're from Europe, I'd try contacting a local company. Neon sign manual manufacture is still very much alive, and I doubt the people that make
them wouldn't want to make a custom order. Consider that the price of the tubes depends on their length and complexity. Short and straight tubes
should be quite cheap.Mixell - 29-5-2012 at 09:12
Well, I could purchase a neon tube, may be even a tube of another noble gas, and then what?
I prefer buying kit at a once.
And I am getting them for 6.5$ each, excluding shipping (which is quite pricey), 15$ is the resell price.Endimion17 - 29-5-2012 at 11:42
That's why I've said - custom order. They could fill it up with all the noble gases, except radon, of course.
I see no reason why they couldn't make for example an iodine tube if you mail them few crystals. (For mercury tube, a simple germicidal lamp will
suffice.)
Neon tube bending is one of the few old style modern jobs that requires actual human crafting skills, and I'm sure they wouldn't mind making something
new and exciting, because they mostly just work with standard tube gasses and like art.
There's one more solution. If you have a decent vacuum pump and a required power source, you can order custom made tubes with electrodes from a
flameworker, and then fill them with whatever you want, reducing the pressure and watching the glow.
But 6.5$ seems a reasonable price if you don't want the trouble with all that.99chemicals - 29-5-2012 at 11:51
How would you get sulfur in GAS a discharge tube? You could voporize it but then it would crystalize on the sides of the tube. I know sulfur has the
most alletropes of any element. Is there one that is stictly a gas?Mixell - 29-5-2012 at 12:45
I imagine it is a gas because of the low pressure inside the tube.
And I live in Israel, not in the EU, thins here are pretty expensive (a spectrum discharge tube costs around 50-60$ excluding shipping). I don't
custom made objects being cheap here.
Also, the same Indian company sells a power supply for 56$, I could have tried to make my own, but I do not want to risk it.
Too bad the shipping is around 65$...Endimion17 - 29-5-2012 at 13:30
The gas discharge tubes contain pretty much nothing. The gasses are at low pressure, therefore a very small amount of sulfur would suffice, probably
like a very small grain of salt. I think sulfur sublimes well enough at room temperature and very low pressure, but if that doesn't help, heating the
tube a bit would help.
Iodine would work like a charm, though it would probably corrode nickel electrodes, turning it volatile, therefore introducing nickel spectrum.
There are other possible arrangements, like this one, with high frequency radiowaves which do the trick for mercury because it's readily ionized. That wouldn't really work for sulfur, I
guess. Be sure to watch the entire video, it's quite cool.barley81 - 30-5-2012 at 07:40
It actually does work with sulfur. Sulfur in an evacuated tube is excited by microwaves. There is a video on YouTube about a DIY sulfur lamp.
I don't think microwaves are the thing that powers the mercury lamp in the video I posted. They're not shielded.
But then again, the people in the video are exposing themselves to a UVC source, so yeah... it was a fun era. barley81 - 30-5-2012 at 09:02
I couldn't watch the video because I was at school. When I get home, I'll take a look.
It would be a nice project to make mercury discharge tubes, or any gas discharge tubes. Unfortunately I don't have the resources to do so..Aperturescience27 - 5-6-2012 at 19:35
