Laser Safety Question

[jm82792]

Firstly, I apologize for swinging in here and asking such mundane questions.
I don't have any inclination of owning any high powered lasers since I have 20/60 vision and years before it was 20/400. When your vision sucks (I've never seen 20/20) and your entire life has been shaped like it, then you stick with bright flashlights, and don't retrofit say a spare CNC with a 3 watt diode for fun....
Anyways, I bought a cheap "G301 Green Laser Pointer" from Dealextreme since I though it would be a nice and random cheap gift for a friend.
As with all cheap Chinese stuff I test it first and so forth.
This thing doesn't appear to be 5mw and from what I can infer it could be 35mW to 100mW! I've been careful with it, but there has been some diffused reflections from 6ft away from a satin finished hardwood floor (diffused but mild reflectivity that's somewhat scattering) so for an intensive purposes there has been some exposure. So now that I'm digging and reading I'm hoping no damage was incurred. No reflective things bounced or diverged(?) but I'm a tad paranoid. Later, as test and with precations I shined the beam at my skin, with luck it appears the correct focal length was hit, and it does in fact burn skin very lightly, perhaps to the point where it's barely doing anything at all... I'm not an ophthalmologist (although I've seen my fair share) but there aren't any floaters, spots, or any weird abnormalities... I'm guessing my exposure was what would involve burning ants with a magnifying lens...
Anyways, I'm curious on what these things are normally at power wise.
Not that I can do anything about it, but it will set my mind at ease before I probably cut the unit in half. I know that sounds very rash but I though maybe it was 10mw or something, but it appears this thing is a lot more sinister than that, and I don't want anybody getting a hold of a supposedly safe 5mW unit thats not.

Again sorry for the swing in and out message but your input would be appreciated.

 

[ATprotecter]

A lot of those Chinese 301's can be scattered anywhere when it comes to mW's. A 5 mW can't burn. It sounds like you definitely have something over 40mW for sure. You can't be sure though unless you are able to test it with a LPM. If your eyes were only exposed for a short time, just be careful next time. The damage that happens you may not be able to see or tell. I've had several lasers from DX and the 5mW are sometimes 10mW, and sometimes 50mW. Why cut the unit in half if you are planning to give it as a gift? If the person you are giving it to isn't responsible and would do something stupid, then keep it for yourself and get some safety glasses. Any laser shouldn't be pointed at anyone, so just be safe and you should be good!

Don't worry about a little exposure, you can't reverse it but only be more safe. Also when you shine it, don't look at the dot unless you have glasses. Safety glasses, not eye glasses...

 

[jm82792]

Thanks for the reply and the information on the unit.
It definitely seems to pack a punch, and I'm surprised since usually chinese stuff under preforms. I'm almost daring to say it would work for SLS based 3d printing or so forth..
The statement of cutting it in half is a bit extreme now that I've heard your input. But I can assure you if you (hopefully never) have vision issues, and then find out that you benign thing isn't then you'll get a bit worked up..
I have several young siblings, although I have a lot of dangerous things a laser pointer isn't something I want around... I'll give it to that friend mentioned, as he is intelligent, and doesn't have any small hands that will get into anything. Plus there is a flight path of civilian and military aircraft here (the helicopters are perhaps 500-1000 feet away), so if it's not pointed at themselves it might be at them!
It is rather neat being able to point at anything and see that diffused spot from a mile plus away... Still surprised that a whopping $15 with the 18650 batter will get something like that. I'm assuming they salvage the modules and whatever you get is what they pulled?

 

[Shakenawake]

it's a 532nm? it probably is not IR filtered. non-IR filtered 532nm lasers will emit IR light due to the DPSS nature of the laser. this IR will add to the power without adding to the brightness, making the laser more dangerous

 

[The Lightning Stalker]

If you are feeling a pinch on your skin then it
is >50mW.

 

[hakzaw1]

--

no laser is actually kid safe- and it wrong thinking to ever consider them to be toys.
I dont want 5mW shined at me-nor 4.9 mW or 5.01mW..

worst case is a direct level shot to the center ( and thus lens) which magnifies the power like a mag glass does the sun--so its no longer 'just' 5 mW--

The (now) common 3$ green pointer (NEVER HAS IR FILTER., btw) is NOt the BB gun of the laser world --that would be the 1mW button cell battery red cat toy-- the green is the .22 cal of the laser world-- THNX to regs AFAIK the Chinese no longer bin thier pointers and sell them at priced based on binning- they are all now called 5mW and yes its not uncommon to find a freak that is 100mW--some thought they made different pointers for the powers--not so==they are all the same. ( from each maker)
wierd how some want Overspec and some want 5mW or less-- since you wont be pointing in anyones eyes I dont see the point--

An Orion 532 Skypointer- is exactly 4.9mW- has a filter- very solid- thin beam- super divergence- comes in swell metal case @ ONLY $150--

While you may find a cheapie $3 one that is ~5 mW but ATM those seem to be the exception NOT the rule--

Making laser the forbidden fruit may be a bad idea-
Chidren are not all alike- some seem born to be risk takers- BUT IMHO they need to learn safety along the same lines as is done for hunting guns or target shooting- etc.
anyone who treats every laser as if its loaded(has batts)like a gun and never even points it at something NOT meant top be killed(blinded/harmed) etc- would be doing the world a big favor.

see :
laserpointersafety.com

be safe

Hak

 

[upaa27]

Its probably 50mw+ as you said it stings. Don't shoot yourself with anything 500 mw+ it BURNS.

 

[Marco Polo]

I don't consider the 301 lasers to be dangerous PROVIDED the following are observed:

- Never point it at your own face, or anyone else's
- Never point it at mirrors or anything else reflective
- Never point it at any vehicle or heavy machinery whatsoever
- Always look BEHIND the object you are pointing at, and make sure there is nothing back there that would violate any of the above
- Always think AHEAD about how any observers or bystander might react - are there aircraft in the sky? Do you have crazy, PITA neighbors who might raise a fuss?

Nothing makes a laser more dangerous than careless, thoughtless operation.

If you keep those in mind, you can operate the laser safely. The diffuse reflection from a wall or similar is not dangerous although it will produce after-image spots. Also, be careful carrying it in your pockets as the side switch is very easy to press by accident and you might burn a hole in your pocket. Use the key switch on the end to turn it off if you want to carry it that way.