UV LED saftey concern

[Bionic-Badger]

Or rather than wrecking the ends of your LEDs you could just reduce the input current. In the end the priority will be to obtain a nice looking eye glow at a reasonable output level, otherwise there's really no point in the first place.

 

[The Lightning Stalker]

Not quite.
http://www.edmundoptics.com/technical-resources-center/optics/optical-glass

 

[NO4H99]

I said, "almost" anything clear will stop UV lol.

I know quartz passes UVC, that's why germicide lamps use it.

That's not true at all. Just because polycarbonate absorbs uv light, does not mean that every, or even most, clear things will.

 

[DashApple]

I would say the contacts would absorb pretty much all the UV light and just fluoresces , being low powerd too . I wouldn't think it would be a hazard .


Just a Demo , But this is polycarb goggles Vs a true 10 Watt 365nm led . You can see the plastic blocks all the UV light , with a small amount of visible passing though


IMG_0079[1] by TwirlyWhirly555, on Flickr

I ware the goggles when using the led too .

 

[NO4H99]

^^^UVC is not "even easier to stop" UVC is approaching x-ray wavelength and is most dangerous of all uv light. It is stopped by the ozone layer in the atmosphere.

Also glass will not block uv light - It blocks some UVA, most UVB, and almost no UVC.

 

[Bionic-Badger]

False. Age doesn't mater when it comes to blocking UV light. Just about anything clear will block UV.

Why do you think UV protection goggles are just clear polycarbonate?

The lens in your eye is not polycarbonate, and the crystalline structure of it changes as your body ages. You can read about it in various papers such as this. There are even studies investigating replacing peoples' lenses with artificial implants that are not literally yellowed with age to affect their circadian rhythm due to the eye's lack of response to diurnal light patterns.

 

[NO4H99]

UVC is easier to stop. It is such a short wavelength almost anything will absorb it.

Shorter wavelength does not mean "almost anything will absorb it". In fact, the shorter the wavelength, the higher its energy (E=hf) - making it harder to stop.

Why do you think Ozone stops it?

Ozone stops it because it has the perfect amount energy needed to break the single oxygen bond

And Vacuum UV can only pass though a hard vacuum. Because air blocks it.

Air blocks it because of the molecules in the atmosphere - not because it is absorbed by almost any substance.

Glass does block UVC. Just not as good as the polycarbonate does.

My bad on that one, glass does block uvc

And I have a question for you, can a full spectrum camera pickup 1342nm IR?

No clue, Why? :thinking:

 

[Bionic-Badger]

Silicon isn't that good for those longer wavelengths, and its absorbance drops off quite a bit after around 1000nm. It's essentially transparent around 1500nm -- making it great for waveguides for telecom wavelengths.

 

[The Lightning Stalker]

There is at least one that can.
1342nm DPSS Laser

 

[NO4H99]

And Houston we have a threadjack

Sorry 'bout that OP.

 

[The Lightning Stalker]

Well you can disregard that link. That was the 808nm pump visible in the first picture. I should have
looked more carefully before posting. There is probably a camera out there that can pick it up though. It
looks like you're sailing into uncharted waters.

 

[Bionic-Badger]

Of course It isn't polycarbonate. Just saying your eyes will stop the UV.

No, your assertion was that the eye's ability to block and absorb UV is not a function of age.

 

[NO4H99]

^^^Are you really trying to say that your eyes don't change over your lifetime?

 

[chipdouglas]

people also used to believe the world was flat

Michael.

 

[chipdouglas]

Ultraviolet Radiation and Sunglasses: How To Protect Your Eyes

a quote from the above website

"Also, children are more susceptible to retinal damage from UV rays because the lens inside a child's eye is clearer than an adult lens, enabling more UV to penetrate deep into the eye"

 

[Bionic-Badger]

In my belief, eyes are eyes.

This is what supports my belief.

Eyes are eyes regardless of age.

Yes, well your belief doesn't hold up to science. Eyes are not just eyes as a function of age, just as ears are not just ears. There have been numerous studies that show that the absorbancy of the lenses in human eyes change over the course of their lifetimes. Even the eye's ability to filter blue light -- not even UV -- changes over time, with younger people able to see those wavelengths more easily than older people.