How to Build Home Made Laser Power Output Meter

Re: How to Build Home Made Laser Power Output Mete

I will be off to the radio shack here soon....I have TONS of components, but not the right mixture to get started....I will post progress, etc as it happens

Re: How to Build Home Made Laser Power Output Mete

Kenom said:

Alright. SenKat says he likes math. I hate math so I'm puttin this baby in his hands or yours. I havn't even really won the bid on the module yet but I'm sure I will. SenKat has already taken a look at the .pdf that they send out with it and it claims there is a bit of error involved with it as there is also a bit of math that needs to be done for different wavelengths. I'm not too particularly impressed with this unit and if I don't win this one the next thing I'm saving money up for is a Coherent Lasercheck. I want something with certainty not ballpark. I've got a LED that gives me ballpark.

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The unit is calibrated for 633nm and he provides a very simple chart for the correction factor, I don't see much of a big deal with that if it all works. OF-COURSE it's not going to rival a Coherent Lasercheck, I would not expect that of a $20.00 unit, versus a $335.00 unit; surely you didn't expect it to?

Re: How to Build Home Made Laser Power Output Mete

Not at all.  well kinda.  ok I did.

I was Hoping that it would work cheap. I'm not very knowledgeable about this kind of thing and I'm still learning. I knew it wasn't going to be tooo horribly accurate but at least a lot closer than "ooooh it's around 30 - 70mw." I can tell that with my led. Ah well. Just like everything in life there is no cheap way of doing something good. You can do it bad for cheap but not good. "I bot this here puter at the salvation army fer $5 'an i can't git it ter run quake but it shur does type good.!"

Re: How to Build Home Made Laser Power Output Mete

Kenom said:

Not at all. well kinda. ok I did.

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Let me clarify, I do expect it to be a lot more accurate than the led method, which I found to be a complete joke. But I don't think it will rival the coherent. I would expect it to be fairly accurate and the results to be repeatable. If it shows 100mw, I'd expect it to be close to what the coherent would show, and it should know the difference between a 5mw, 10mw, 50mw, 100mw, etc; with a certain degree of accuracy based on the power factor chart and the ND filter added to the mix.
I do have hopes it will turn out to be a cheap and fairly accurate method, rivals the led method; and close to the coherent.
For $20.00 & a ND filter, I think that would be a great bargain.

Re: How to Build Home Made Laser Power Output Mete

Let's hope with some real patience and handywork this can be a reasonable power output checker for the money. In saying that a rough guage to see what a laser is doing

Re: How to Build Home Made Laser Power Output Mete

Well, Regardless, I have one that i've bid on and will undoubtedly win. I know that it will turn out to be ok for a lower priced LPM. I would like to go back to school and learn electronics and whilst there take a course on math. Never was very good at it. I'll let the people with the know how figure out the hard stuff till then..

I'm suprised I didn't get a hardy har from the joke I posted in my last post. I was going for dumb southerner meets pc. ah well comedy is wasted on some. Way to stay on topic LOL.

Re: How to Build Home Made Laser Power Output Mete

OK so I got my unit and here is what I found, first off I'd like to start off by saying his Ad is *very* misleading; here is a paste/copy quote right from his Ad, Please notice the Color for that part of his message in his Ad on ebay, it is meant to get everyones attention, ie; the most popular Laser these days is Green 532nm. Begin quote;

Simply attach a 9 volt battery and connect the output to a Digital Multi-Meter of your choice.
(Inexpensive Digital Multimeters can be purchased on eBay for less than $10.00)
Set the scale of the DMM to 200mv... shine the Laser beam onto the
Silicone Optical sensor and read the Laser Power output directly
without the need to calculate a mathematical formula.

After you pay for the auction and after he ships it out first, he'll then send you a link to d/l a pdf file that clearly states you *must* convert the readings for any wavelength other than 633nm which it is set for, which will give you a "ROUGH reading" his words, not mine. Back to the top of my message now, it is in GREEN no-less and it clearly states "without the need to calculate a mathematical formula" Do you think the color chosen only for that part of his Ad was for a reason? I do, it was to give you the idea it works out-of-the-box for Green Lasers, Bait taken!

You may not have paid too much attention to the picture at the bottom of his Ad, but you'll see a Red Laser being used for his Demo, of-course he used a red laser to demo it, it is accurate for that wavelength only. I wonder why he didn't state that in his Ad and not use Red type when he described the portion I just posted in his message, Geee I wonder, or perhaps why didn't his demo use a green laser

Now to the readings with it, using brand new Eveready Alkaline batteries out of the package with an exp. date of 2014 on a Red 635nm 5mw LeadLight Laser from AtlasNova, I get a reading of 6.2 Peak & a stable reading of 5.6mw, sounds about right.

Now using a another set of brand new out of the package Eveready Alkaline batteries exp. date 2014 with a Green 532nm 5mw LeadLight Laser from VitalSpirit I get a Peak reading of 17.0 (have to then do the math, 1.55 x 17.0 = 26.35mw) Stable reading of 14.5 (do the math again, 1.55 x 14.5 = 22.475mw). I really don't think my un-touched 532nm is putting out all of that power.......thoughts?

Oh by the way, the $9.95 postage paid is typical of ebay "scams" he won't let you combine orders, and all the "package" is, is a simple first class ENVELOPE.....well I heard 1st class rates have went up recently, but he gives that a whole new meaning.

Update: OK so I had some time today and I tested the Red 5mw 635nm on a Professional Laser Meter and I got only 4mw for it. For the Green 5mw 532nm I got 6mw. So as you can see by the above original test I done with the ebay sensor, it really is not that accurate.

Re: How to Build Home Made Laser Power Output Mete

I have an idea - send me three items, please - I can put this whole thing up to the test. If you were to send me the red, the green, and the power meter "device" - You already sent me the PDF file...but if you could send those to me, via USPS WELL PADDED Priority mail, I can then test those results here, with a vast sampling of items, as well as put your two lasers to the test with my power meter. I would pay return shipping (insured - I do NOT want to take any chance on boogerring up your items) and publish the test results for everyone, so we can holler SCAM or NO SCAM. So - what do you say ? I would test everything the same day as I receive it, and get it back to you in the mail the next shipping day. It COULD save some folks some cash - or if it proves to be genuine, boost the hell outta his sales !

Greg

Re: How to Build Home Made Laser Power Output Mete

I've already told you that I'm sending you the one i'm purchasing SenKat.  I've paid for it and am waiting for it to get shipped to me.  Once it arrives I'm not even going to test it or play with it just forward it on to you for testing purposes.  I am sure that you have plenty of red 5mwer's and maybe a green 5mw'er.  I recall you got a core.  so look for those in the next week or so.

Oh still no lasers in the mail. Scared the mail lady when she opened up my mailbox though. heheh.

Re: How to Build Home Made Laser Power Output Mete

Oh crap - I forgot about your offer ! LOL Sorry about that (DOH !)

NOTHING IN THE MAIL ?? WTF?????

Re: How to Build Home Made Laser Power Output Mete

Maybe you can check the status. My mail lady is getting tired of seeing me pop out of my mailbox. It's not my fault it's been raining outside and I dont' want to get wet.

Re: How to Build Home Made Laser Power Output Mete

LOL !!! I will - and I will check with my wife, who cannot seem to find the dang receipt - at least it hasn't been taken out of our bank account either ! I'll let you know tomorrow, man - hit me up on IM, I;ll be logged in at work.

Re: How to Build Home Made Laser Power Output Mete

Kenom said:

I've already told you that I'm sending you the one i'm purchasing SenKat. I've paid for it and am waiting for it to get shipped to me. Once it arrives I'm not even going to test it or play with it just forward it on to you for testing purposes. I am sure that you have plenty of red 5mwer's and maybe a green 5mw'er. I recall you got a core. so look for those in the next week or so.

Oh still no lasers in the mail. Scared the mail lady when she opened up my mailbox though. heheh.

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Cool, I'll then leave that up to you then; I'm extremely busy this week so I don't have anymore time to devoted to this project. However I will say the tests I conducted were done carefully and accurately with a $450.00 Beckman Bench DMM.
I have a little more than a dozen Lasers in my collection and I plan some more tests probably next week using some of the other Lasers, the ND8 filter; and then comparing all of that on a professional LPM.

Senkat; I'm good to go, so when I've had a chance next week to finish up all of this I'll post some more. In the meantime when you get the HLPM-2 it would be good to see your results too.

Re: How to Build Home Made Laser Power Output Mete

I'm anxious to see the results of this.

Re: How to Build Home Made Laser Power Output Mete

Kenom said:

I'm anxious to see the results of this.

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Hey CPF is back online again, I'm on it now

Re: How to Build Home Made Laser Power Output Mete

WHOOOOHOOOOOO.