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ArcticMyst Security by Avery

Little question...

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Apr 26, 2013
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I do not own a LPM and i know the only way to know the real output is by testing it with an LPM.
But isn't it true there is a certain limit of mW is needed to be able to do certain things with a laser such as burning?

Now i have 2 green laser pointers from which i believed they were 30-35mW each.
But now i have reason to believe they are atleast 50mW.

This is what i am able to do with them:

1. Beam is clearly vissible at night and vissible in dim lit rooms
2. Laser reaches anything you can see...(except most clouds)
3. Melts thin black plastic like garbage bags

And what i found out today.

4. They both sting my skin after a few second from really close range

Now i remember reading somewhere that a laser below 50mW wont sting your skin...

My question is, based on what my lasers can do in what mW range would you think they are?

(i'm not looking for a clear answer like ''50mW'' Because i know this is not possible to know without an LPM but i am looking for a answer of what mW they would at least have to be to be able to do these things)
 
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Trevor

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All of those things you list depend on the diameter of the beam in addition to the power.

There's no way to know the actual power of a laser without an LPM.

Trevor
 
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The diameter is really small assuming it means how wide the beam is?

then it is about as small as it can get ^^
I know i can never found out teh real output without an LPM i just would like to know what would be the minimum power needed for the things they can do?
 

Trevor

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The minimum power required to do different things is (almost) irrelevant. What matter is power density (power per area). The "minimum" beam diameter is on the order of microns.

You can't mark black plastic with a 10mW laser with a 1mm beam.
You CAN mark black plastic with a 10mW laser with a 0.1mm beam.

It depends on how much power is concentrated in a certain area, and the "minimum" power to do something has as much to do with power as it does beam diameter.

Trevor
 

IsaacT

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Measure the beam's diameter. Small is not always the same small as another small. And a small difference in diameter means a big difference in power density.

Also, different parts of your body can feel heat more intensely than others. If I shine a laser on my lips, I can feel the heat down to the 5-20mW range.

And thin black plastic isn't too difficult to melt, especially if you can focus your lasers. You really do need an LPM. Look in the "Members with LPM's" thread and see if there is someone near you who can measure your lasers. Alternatively, contact a university as many will have a Laser Power Meter and they might allow you to measure yours.
 
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Ah okay i didn't now that yet...

I thought a minimum amount of power was needed for certain things
(i got that from the lazerer powerchart) But then i guess that chart is not accurate?
 
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There are too many variables involved to pinpoint your laser's power. The charts offered by laser companies are just very very broad and general statements as to what a certain power can do
 
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Yeah there is no minimum power threshold for burning things necessarily...beam radius matters a huge amount. It's all about power density...the more the better for burning :)
 
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I know what your after but what seems simple in lasers isn't
I have been after the same sort of answers as you but haven't had much luck yet
I would love ball park figure myself, but how focused is beam is the reply i get back
Assuming the focus is as good as you can get what is minimum power that will ignite a match, pop balloon, melt black plastic etc at say 10cm and see what answers we get.
 
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Thanks for the replies, i never knew there as so much that effected it.
I guess i will just have to get them tested some day then ^^
 




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