I should have said "a IIIa laser is a IIIa laser" Brent --- Jim Gibson <xajax99@yahoo.com> wrote:
Brent The one I got from Howey Glattor is The 532nm green holographic collimator.
Brent Watson <brentjwatson@yahoo.com> wrote: Both red and green lasers fall into the same classifications. A IIa laser is a IIIa laser, as long as it falls between 400 and 710 nanomemters. Red is around 700 and green around 500.
Brent
--- Kim Hyatt wrote:
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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