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HLDPM12-655-5 laser class help

michael22

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Hello,

I recently bough a HLDPM12-655-5 655nm 7mW laser and I would like to know in which class does this laser belongs to, 2 2M 2R IIIa IIIb ? I don't really know and I would like to know how safe it is... (if I can get my eyes damaged when looking for a short time at it or at the reflection by mistake)...

Thank you !
 

michael22

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I know :( I read that but I don't really understood in which class this laser is... newbie :( I've also read the datasheet but it's for several models and it doesn't say for each if it's IIIa or IIIb and does not mention the 2M or 2R class...
 
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sinner

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IIIb is 5mW-500mW
So it's in IIIb - at 7mW not harmful as the blink reflex would save you before it does damage the eye.. BUT if it is passed through magnifying optics, you should be careful.
 

Multimode

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The class refers to the completed product i.e you can have a class 4 laser fully enclosed aso the beam is not accessable, the "system" then becomes as a class 1 laser for example.
ATB
MM
 

tsteele93

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IIIb means it IS dangerous because the blink reflex won't save you.
Technically IIIb is dangerous, but if it is truly a 7mW red then I am fairly certain that it would qualify as a safe laser. There has to be a LOT of headroom built into those ratings and none of us would consider a 7mW as dangerous or treat it with any significant degree of caution.

If we are HONEST, I bet there aren't many folks on here who treat anything less than 50mW with any real caution.

For me, 50mW is where I start reaching for goggles. Under that and I just haven't seen any real evidence of significant danger.

I'm not saying you can't hurt yourself with 10mW but I think it is HARD to do...
 

Wolfman29

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It's sort of a problem around here that we don't treat them as dangerous. There is headroom built into those, but only a 50% headroom. Those stats are 50% likely stats. This means that, if you take >5mW into the eye, there is a 50% chance that you will take permanent damage.

Is it a risk that you're willing to take? We should probably be more careful around all lasers, to be honest.
 

tsteele93

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It's sort of a problem around here that we don't treat them as dangerous. There is headroom built into those, but only a 50% headroom. Those stats are 50% likely stats. This means that, if you take >5mW into the eye, there is a 50% chance that you will take permanent damage.

Is it a risk that you're willing to take? We should probably be more careful around all lasers, to be honest.
First, let me make sure that I don't come across wrong - Wolfman, you KNOW what I think about you. You are one of my absolute top favorite people on here. I've bought a laser fom you (which is still my best red right now) and you have helped me understand electronics like no be else. Plus you also impressed me with the way you handled the RE thread.

So that all said, please don't take it personal if I argue with you in this thread! :D

I don't buy the 50% chance idea. We should research it more. But I am pretty sure that taking 7mW in the eye is 0% dangerous in the real world. You are still gonna blink and it isn't gonna harm you. 10mW is probably the same. 20mW might be riskier, with maybe a 1%-5% chance that you will injure yourself, etc...

There are several reasons I say this.

First, we all know that kids can buy 50mW+ lasers that are labeled as 5mW on Amazon or EBay all day long. They sell thousands and thousands of these things, and there is no evidence of increasing incidents of eye injuries caused by lasers. I'm too lazy to go look that up, but it is probably in the safety goggle thread.

Second, you know the FDA put a TON of safety headroom in the 5mW limit. I'm betting that it was more like a factor of ten, which is one of the reasons I PERSONALLY choose 50mW as my "safe power" limit. (I should note, I have two little kids aged 3 and 5 - for them I have a 635nm laser that I have tested at 3mW and they play with those under moderate supervision - no way I would give a little kid a 50mW. I am saying for a teen/adult with enough awareness not to point it directly in the eye.)

Third, I'm not going to call anyone out - but there are builders HERE that admit to not having goggles at all. ;)

Anyway, please know that I enjoy debate, but I hate that arguing on forum's sometimes creates "friend or foe" categorization. You are in my friend category and I'm arguing IDEAS not people.

So give me heck, tell me all the ways I'm wrong and I'll argue back. I just don't want you to be mad at ME. :)

NOTE: it would be very interesting to find out how the FDA came up with 5mW and what the numbers actually mean. Hmm..
 

Multimode

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Here is a little bit of info I found:-


Class 1
SAFE
Either (1) output is so low it is inherently safe or (2) the laser is part of a totally enclosed system.


2Class
LOW POWER-visible CW and pulsed lasers
In the case of CW lasers eye protection is normally afforded by the natural aversion responses including the blink reflex. Hazard can be controlled by relatively simple procedures.

3Class A
LOW-MEDIUM POWER
Extension of Class 2, where protection is still afforded by the natural aversion responses, but direct intrabeam viewing with optical aids may be hazardous. This must be controlled.

Class 3B
MEDIUM POWER
Hazard from direct beam viewing and from specular reflections ( i.e. .off shiny surfaces). Eye damage can occur in less than 0.25 second. More detailed control measures are necessary.

Class 4
HIGH POWER
Not only a hazard from direct viewing and from specular reflections but also possible from diffuse reflections (off rough surfaces). May also ignite flammable materials. Extreme caution required.

and some info from Wiki so take it with a pinch of salt ;-)

Lasers are usually labeled with a safety class number, which identifies how dangerous the laser is:
Class I/1 is inherently safe, usually because the light is contained in an enclosure, for example in CD players.
Class II/2 is safe during normal use; the blink reflex of the eye will prevent damage. Usually up to 1 mW power, for example laser pointers.
Class IIIa/3R lasers are usually up to 5 mW and involve a small risk of eye damage within the time of the blink reflex. Staring into such a beam for several seconds is likely to cause damage to a spot on the retina.
Class IIIb/3B can cause immediate eye damage upon exposure.
Class IV/4 lasers can burn skin, and in some cases, even scattered light can cause eye and/or skin damage. Many industrial and scientific lasers are in this class
 
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sinner

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Thats true Tom, i do hate to agree with the notion that anything below 50mW we dont bother safety goggles.. Hell no one would have wore them with swim's overspecs or super overspec's for that matter although they reach upwards of 80mW.. Here's the honest truth, I no way applaud it and im not proud to say that either.. The new system of classification does seem to be very specific on the beam collimation, divergence, passing through magnifying optics etc etc..

Consider a 3mm diameter beam with 0mRad on it.. At 5mW it will be A LOT less dangerous than a 1mm beam diameter or when defocused from infinity and at the sweet spot we call burning point where all of the light is gathering would not be a 5mW anymore but the intensity per unit area will be much higher..

Divergence on the other hand is very important , if the divergence is high as in case of green's, they will become safe at a specific distance because the scattering will reduce the intensity of light per unit area or in other words milliWatts..
 

Wolfman29

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@tom: You don't have to worry about arguing on the internet. I'm not one of those people who gets frustrated because of debates. I'm like you - I love debating! And I appreciate all of the compliments. Made my face go red =p

That said... I do tend to agree with you. I just don't think we should advertise anything above 5mW as being safe. Clearly, the FDA thinks they are dangerous to prevent importation. If it were physically impossible to take eye damage from 6mW, they wouldn't ban them. That would be silly.

Even if they are relatively safe, even if the chance is 1%... that doesn't mean you should risk it! Would you want to be the 1% who loses his vision (or at least takes permanent damage)? I know I wouldn't.

And yes - @sinner: Divergence is very important. However, due to the nature of coherent light, I am pretty sure that the eye will always focus all of the coherent light entering it onto one point on the retina. That being said, no matter the divergence or size of the beam, whatever enters the eye will cause damage.

I read that somewhere - not sure if it's accurate, so if I am wrong, correct me!
 

tsteele93

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@tom: You don't have to worry about arguing on the internet. I'm not one of those people who gets frustrated because of debates. I'm like you - I love debating! And I appreciate all of the compliments. Made my face go red =p
I kind of figured that you weren't likely to take offense, but I do get frsutrated sometimes when debates turn into arguments and arguments over ideas turn into not liking someone - when in real life we could get along fine.

I tend to debate rather "enthusiastically" for some people, so I just wanted to preface my comments to make sure you knew that I wasn't arguing with YOU, just some of the differing opinions and ideas we were having on this paricular teeny weenie topic.

Some people have trouble separating those things. I think the forum could do with a little reminder that we are all a bunch of different (mostly) guys who enjoy lasers and maybe optics and electronics and all things geeky and if we did IRL meetups we would probably have a good time together. But on the internet we lose those visual cues that might let us know when to back off or ease up when we have stepped too hard on someone's toes, etc...

And I meant the compliments. There are lots of people on here with a solid knowledge of the electronics, but you are able (and willing) to explain them in a way that really makes it easy to understand. I really do appreciate it. :)

Enough brown nosing :D back to the topics. I can't even see my iPad very well right now because I am in the middle of a Light Migraine and probably will be for another 20 minutes. I'll come back then.
 




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