Brent, in what classes do both red and green lasers fall?

-----Original Message-----
From: Brent Watson [mailto:brentjwatson@yahoo.com]
Sent: Monday, August 11, 2003 3:36 PM
To: Visit http://www.utahastronomy.com for the photo gallery.
Subject: RE: [Utah-astronomy] Green laser backlash

The following is from CFR 21 part 8 section 1040.10
(b), where these things are codified and damage limits
defined:

(5) 1 Class I levels of laser radiation are not
considered to be hazardous.

(6) 2 Class IIa levels of laser radiation are not
considered to be hazardous if viewed for any period of
time less than or equal to 1 x 10\3\ seconds but are
considered to be a chronic viewing hazard for any
period of time greater than 1 x 10\3\ seconds.

(7) 3 Class II levels of laser radiation are
considered to be a chronic viewing hazard.

(8) 4 Class IIIa levels of laser radiation are
considered to be, depending upon the irradiance,
either an acute intrabeam viewing hazard or chronic
viewing hazard, and an acute viewing hazard if viewed
directly with optical instruments.

(9) 5 Class IIIb levels of laser radiation are
considered to be an acute hazard to the skin and eyes
from direct radiation.

(10 6 Class IV levels of laser radiation are
considered to be an acute hazard to the skin and eyes
from direct and scattered radiation.

For the complete text, got here:
http://www.lasersafety.net/CFR/cfr_title21_part1040_10.html

Brent

--- "Lambert, Aaron"
wrote:
> Hello all,
> Just delurking here for a moment... For those of
> you who
> own green lasers already, where have found the best
> place
> to purchase them are? The best price I have seen is
> EBay
> for around $70. I always wonder about the quality,
> etc of
> EBay items that are mass-sold, though. I have
> considered
> buying one so it is easier to point out
> constellations for
> my kids (ages <= 6) and for youth groups (ages
> between 12
> and 18). Pointing with my finger works pretty well
> for
> showing one or two people, but I have tried that
> while
> camping with a group of 10+ and they cannot all
> follow my
> arm and finger very well.
> Also, I understand that they are fairly dangerous
> in
> that they can cause severe eye damage if the beam
> hits
> someone in the eye. Is this true? Obviously I
> wouldn't
> intentionally let a kid (old or young) get a hold of
> one,
> but I remember being fairly curious and resourceful
> as a
> teenager... :) Anyway, I would appreciate any
> comments or
> insights from the group.
>
> Thanks,
> Aaron Lambert
>
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>
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