Quote:
Originally Posted by pdupiano /img/forum/go_quote.gif
Some possible reasons why medical UV lights are expensive:
1) Specific spectral range:
-While a large range of LEDs may produce 395nm wavelengths, they may also produce a wide range of wave lengths and the over all "power" is decreased (Bandwidth versus intensity I suppose). As you mentioned in your post, direct sunlight would work too (you're guaranteed to get wavelengths in the region you need). But the overall broad band of spectral waves is so great that the amount of actual "power" delivered to the molds may not be enough to cure them (at least in a tolerable amount of time).
|
Actually, most UV LEDs have a very narrow spectral output from what I've seen, i.e. 390-410nm, 395-405nm, etc. However, cheap UV LEDs that are the equivalent to what you would you would use as a power indicator in a piece of electronics only put out around 100mW or less. These LEDs made for dental curing come in 5W and 10W packages, that's the reason they're so expensive. I would imagine any 5 or 10W LED regardless of its spectral out put would be equally expensive. But then again, to equal the 5W output you'd have to by 20 100mW LEDs, at about $1 a piece you're not saving that much.
Quote:
Originally Posted by pdupiano /img/forum/go_quote.gif
2) UV LED lamps/lights may not exactly be UV in that what you buy commercially is in the visible light spectrum but no one really checks if its beyond that. And to be honest I'd be pretty damn worried if UV LED flashlights were actually in the UV range. The melanoma rates in the world would have tripled or doubled by now from kids playing with flashlights.
|
I believe most people can see light at starting at about 400nm, and UVA, which is 320-400nm, is the least dangerous because it doesn't cause direct DNA damage, unlike UVB (280-320) and UVC (100-280). UVB in sunlight is what gives you a sunburn; UVC in sunlight is mostly filtered out by the atmosphere, and is the most dangerous - it's used for sterilization because it basically destroys DNA. So, yeah, you can actually buy a
UV flashlight. Most cheap UV flashlights are probably in the 390-410 range. I say cheap because you can buy more expensive UV lights at 365nm that are made specifically for
forensics applications. Apparently things that flouresce under UV light do so the best at 365nm. Not to mention the fact that you can buy
UVC sterilization lights for home use. How's that for dangerous?
Quote:
Originally Posted by pdupiano /img/forum/go_quote.gif
3) Built in UV protection. Certain medical practitioners do rely on UV lights, I noticed my dentist using something similar the other day to cure a mold (and yes I did ask her if she could take impressions of my ears... she said no). Looking at the device, its made of a single LED, with a shield and a way of concentrating the light to a particular spot.
|
That sounds like the
handheld UV spot curing lights. That's what those 5W and 10W LEDs from LEDENGIN are used for.
Quote:
Originally Posted by pdupiano /img/forum/go_quote.gif
4) Light concentration/intensity. Along the same lines as a laser, certain optic devices need to be concentrated some how. Based on what I saw at my dentist's office, it doesn't seem like its too complicated, but then again I wasn't exactly allowed to take it apart and tinker with her equipment. I remember that in highschool we were able to make our own electronics projects and half my class chose to make laser pointers because the circuitry was a simple series circuit with an LED and resistor....lazy bastards. But anyway only 2 students built the laser correctly because they bought the proper lens that would concentrate the beam well enough to create a laser pointer, while the rest of the class tried to use lenses they got from flashlights and other random junk they bought at home depot.
|
I don't know. I think they're basically just like flashlights with a reflector and a lens.
Quote:
Originally Posted by pdupiano /img/forum/go_quote.gif
Now I'm not saying that this all amounts to several hundred dollars worth of equipment, but what I am suggesting is that you may want to look into the safety aspects of this before moving forward (remember the skin rash issues?). If you really are working in the UV spectrum, take the necessary precautions to prevent getting skin cancer, the last thing we would want, would be skin cancer on your ears.... because then you would have to take new impressions every month due to the changing shape of your ears.
|
I'm sticking with my "it's expensive because it can be" argument. If those Loctite Spot Lights are just a flashlight with an LEDENGIN 10W LED (which, granted is like $120 by itself) then there's no reason why it should cost $1000. Other than because they only people buying them are charging them to their company, and buying a piece of necessary equipment for $1000 is something a company isn't going to think twice about because it will end up paying for itself in no time.
No doubt, messing around with a UV light is dangerous. You would certainly need UV safety glasses. But using a UV light a handful of time for 30 seconds at a time is probably going to expose you to as much UVA as you would get standing out in the sun. There are actually OSHA guidelines for how much UV exposure is safe since there are industries where workers are using UV light on a regular basis. We actually got a new fume hood in one of the biology labs at work that has a UV light in it for the purposes of sterilizing it. Maybe I'll just stick my IEMs in there for a couple minutes.
Now
this on the other hand...