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.
