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ArcticMyst Security by Avery

IR heaters??

Joined
Jul 15, 2010
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OK...I'm probably missing something fundamental here, but could someone explain to me why an IR heater such as....

Link-Quartz Infrared Heaters

is not dangerous, when an IR beam from a laser is?

I know the IR from the laser is collimated and fucused but why is a space heater, designed to output way more IR power than most cheap lasers, considered safe.

I have tried numerous searches on here as well as google but it's just not clicking with my meager understanding.

My wife uses a consumer grade version of these quartz IR heaters all the time in the winter, and it just came to mind today that they are an IR source.
Is thermal IR radiation different than the simi-visable IR radiation from a laser source?

Thanks,
Rod
 





Joined
May 4, 2009
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I'm pretty sure that these heaters emit IR radiation with a wavelength long enough to not
pose any threat to your vision. They produce wavelengths far longer than the light
produced typical NIR or IR lasers. I think i read they produce radiation with a wavelength
around 2~3mm or so. I'm pretty sure at certain point, wavelengths get too long to be
transmitted through the fluid in your eye, anyone feel free to correct me :)
 
Last edited:
Joined
Mar 26, 2010
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It's all about the power density for what your talking about. Wavelength has a bit to do with it since the heater is a lot longer wavelength than the IR of a LD, but it really boils down to how much area that power is spread over. Your heater may have higher power, but that power is getting spread over a LARGE area. With the laser, it's all pretty much ending up in one point.

Think of it like this. The sun's rays don't burn stuff spread out over an area.. but focus them down to a single point with a lens, and you can melt pennies... Same principle.
 
Joined
Jul 15, 2010
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OK. Thanks for the replies. So it's a combination of factors.
The wavelength being much longer and the power density being lower.

That make sense.

I appreciate your time.

Rod
 
Joined
May 2, 2008
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I am surprised no one mentioned lasers being coherent light :whistle: which is a huge factor in their power.
 




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