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FrozenGate by Avery

Estimate the mW of my laser?

S

Snipeye

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I bought it off ebay, here:

532nm 70mW Green Module w H TTL Modulation Green Laser G50 Sepcial OFFER | eBay

But I don't know if it's really 70mW, like it says. It draws 400mAh (though the TTL only takes .5 :D) at 5V, and the dot is EXTREMELY bright, right on the verge of being painful to look at. I won't stare for very long if/when I do, couple seconds tops.

When pointed directly at skin, you CAN feel it - it starts to burn a bit. Tested, and at close ranges, it can burn very small holes through black duck tape.

Any other tests I should run to try and estimate the actual output?

Thanks!
 





I'll guess it's anywhere between 1 and 100mW.

Damn you Livinloud, ya beat me! haha
 
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Snipeye said:
Any other tests I should run to try and estimate the actual output?

Thanks!
Click to expand...
I think you covered every imaginable idea to determine the lasers power. The only test left I can think of is using a LPM, your welcome :)
 
*eyeroll* Thanks, guys, that's perfect. ;)

I know I can use an LPM, and I know that some people on the forums are willing to do that for free if I cover shipping, but I'm working with/on it now and would really rather not ship it off and wait for a week to get it back.

Ideas?
 
Roll your eyes all you want, we're still going to say to use an LPM because it's the only way to accurately measure a laser's power.

I have a green laser that is supposed to be 100mW. It could be 50mW or 150mW for all I know. I'll be buying an LPM in the next few months. Until then, I find it useless to guess on it's output because I will 100% be wrong.

EDIT:

Since it doesn't sound like you'll be getting an LPM or using another person's, This is probably the closest you'll get to your answer.

 
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I agree that it is veryvery hard to estimate the laserpower with higher powerd lasers.

At this power, you can do some tests:

Is it able to pop a balloon? (which color, at what distance, how long does it take)
Is it able to burn a match? (same as above)

Do divergence and beam diameter measurements.

When you did these things above, you can upload a vid here (match burning, balloon popping)and I can give you a +/- 10mW guess. Also comparing to my green lasers with similar power and the effects on balloon / match.
 
DJNY said:
I agree that it is veryvery hard to estimate the laserpower with higher powerd lasers.

At this power, you can do some tests:

Is it able to pop a balloon? (which color, at what distance, how long does it take)
Is it able to burn a match? (same as above)

Do divergence and beam diameter measurements.

When you did these things above, you can upload a vid here (match burning, balloon popping)and I can give you a +/- 10mW guess. Also comparing to my green lasers with similar power and the effects on balloon / match.
Click to expand...

Homework'd
 
I tried - it can pop a black balloon at 2 yards in about 5 seconds, and I could not light a match (stick kind, not matchbook), even holding it almost right next to the emitter - though I did see a very faint amount of smoke. I may not have been holding it perfectly still though. Do you still need the divergence measurements?

EDIT:

Did a couple really quick divergence tests - I have a 1/4" point at about 1 foot, and that expands to roughly 3/8" at 15'.
 
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my Dragon Lasers 75mw viper acts about the same. pops balloons but no match lighting. I have never had it metered though
 
You can use this tool to calculate the divergence.

Takes about 6 seconds here with a 73mW laser (1.4mRad beam diameter, 1.6mRad divergence) and a small black balloon at similar distance.

Guess you´re fine with yours, it should do around 70-80mW as well !


As some other guys pointed out, much better (not exact) measurements you can only get with one of the hobbyist sold around here.
 
Excellent, thanks for the help! It's (pleasantly) surprisingly powerful for the cost - only $30. Now to do some fun things!
 
Snipeye said:
the dot is EXTREMELY bright, right on the verge of being painful to look at. I won't stare for very long if/when I do, couple seconds tops!
Click to expand...

Wait....doesnt that mean...YOURE NOT WEARING SAFTEY GLASSES!!!!!!:scowl::tsk:
 
nazmazzer72 said:
Wait....doesnt that mean...YOURE NOT WEARING SAFTEY GLASSES!!!!!!:scowl::tsk:
Click to expand...

You don´t always need laser safety goggles when handling the laser with care (and you´re experienced enought to do so).

I only wear goggles when doing some beamshots, teaking LPM readings or burning stuff.
 
Focus it, and burn through black thin CD case. Then use formula:

Power(mw) = 1000/time(sec) (edit: more like 2000/time .. check bellow in the thread)

It's VERY rough, of course. From your description it sounds stronger then 70mW. Also 400mA is quite a lot ..
 
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