Power Meter Calibration and Comparison

I donno if selling them would do any good.  We could keep the lasers around as a forum property if you will and continue to pass it on as the need arises.  Ya don't get rid of a calibration laser when all the few meters are calibrated.  You keep it handy for future use.

Oh, and my donation to this would be my time instead of $$. so there's no worry about an elevated price on a laser.

Twas referring to the ambient temp, but heat generated by the laser would also be important to take into account even with a good heatsink. I saw temp briefly mentioned, but not really fully addressed. For normal use, small differences than only cause a laser to shift by a few mW or even a fraction of a mW don't really make a difference. For this purpose though, lets say you're using a 100mW laser, even mW of potential change represents +/-1% margin of error. Considering our meters already have margins of error, as well as our sensors, we'd need to be very careful about keeping the margin of error from getting insanely high.

Kenom said:

I donno if selling them would do any good.  We could keep the lasers around as a forum property if you will and continue to pass it on as the need arises.  Ya don't get rid of a calibration laser when all the few meters are calibrated.  You keep it handy for future use.

Oh, and my donation to this would be my time instead of $$.  so there's no worry about an elevated price on a laser.

Click to expand...

Well with that kind of generosity, we can't go wrong! Looking for parts total for both builds, U.S. list of paying participants!
Jay

jayrob said:

Well with that kind of generosity, we can't go wrong! Looking for parts total for both builds, U.S. list of paying participants!

Click to expand...

How ever it shakes out, I'm in.

Peace,
dave

2 Flexdrives.   $40
2 aixiz modules $10
red stonetek laser diode $20
Bluray 803t $25
2 dorcy hosts $40
total cost $135.


$135 / 3 contributors = $45 each.
$135 / 4 contributors = $33.75
$135 / 5 contributors = $27.00
$135 / 6 contributors = $22.50
$135 / 7 contributors = $19.29
$135 / 8 contributors = $16.88
$135 / 9 contributors = $15
$135 / 10 contributors = $13.50
$135 / 11 contributors = $12.27
$135 / 12 contributors = $11.25
$135 / 13 contributors = $10.38
$135 / 14 contributors = $9.64
$135 / 15 contributors = $9

from there on it really doesn't decrease much.

Ok great! So now we have our cost for the U.S. group!
$145 (because Kenom shouldn't have to pay the $10 bucks shipping to the next participant) If everybody is ok with this idea, I propose that the order of shipping goes according to who is on the list. Starting with:

Kenom will test and ship to me,
I will test and ship to Dave,

If this makes sense, keep the U.S. list growing guys! It's me and daguin on Kenom's list so far. (I say 'Kenom's list' because he is our fearless point man in the U.S.)
Jay

P.S. electron, I hope you get in on this...with that new meter of yours!

ahhh man you go and change my price and I have to redo the price breakdown per.

Kenom said:

ahhh man you go and change my price and I have to redo the price breakdown per.

Click to expand...

Not sure how everyone is thinking about this, but the way I see it, is how ever many people get on the list, will split the $145 bucks. No other cost to you...you are donating too much already. Everybody also pays the $10 bucks to ship to the next guy on the list...
Make sense?
Jay

Oh...I see your break down now. Lol! We must have been typing at the same time again...

Heck yeah.

$145 / 3 contributors = $48.33 each.
$145 / 4 contributors = $36.25
$145 / 5 contributors = $29.00
$145 / 6 contributors = $24.16
$145 / 7 contributors = $20.71
$145 / 8 contributors = $18.13
$145 / 9 contributors = $16.11
$145 / 10 contributors = $14.50
$145 / 11 contributors = $13.18
$145 / 12 contributors = $12.08
$145 / 13 contributors = $11.15
$145 / 14 contributors = $10.36
$145 / 15 contributors = $9.67

from there on it really doesn't decrease much.

This is great! We're off to the races...

Get on the U.S. list! Next one on gets the lasers from daguin...
Jay

Has anyone thought of putting together a test procedure that all
testers should follow to get similar results? Room temp, Duration of
laser 'ON' time, Number of repetitive tests, Etc. Just to remove any
discrepencies that could/may be cause by the way the test was
performed.

Just my $0.02

People (including me) suggested part of that procedure... on the first page.

Some people keep talking about the temperature as if it hasn't been covered. I even proposed a safe method to totally eliminate temperature from the equation by having people get their own reference laser.

Quote from myself:
Furthermore, I would suggest everyone who has calibrated his meter, to make or obtain his own reference laser (which is long-term stable), and whenever making new measurements, use this reference laser to obtain a correction ratio (to compensate for fluctuations like temperature) This way, ambient temperature has not to be taken into account at all. (when the reference laser is measured right after the calibration laser (the latter one being the one being shipped to everyone)
End quote

To further elaborate, contestants measure their received 100mW calibration laser, say the meter reads "89". Immediately afterwards, you point your own reference laser at the meter, and it might read "76". With this information, the meter itself does not have to be adjusted, but future measurements instead. (or adjust the meter if you insist, it'll even simplify the equations)
In the future, in another season, this person has a laser he wants to know the power of, so it points it at his meter, which reads "232". Immediately afterwards, he points his own reference laser at the meter, which might read "79" now because of temperature differences. Then calculate 232*(76/79)*(100/89) = 221 mW

---

Are there even participants NOT in the US? I would still like to participate (I'm in Europe/Holland)

All we need is about 5 or 6 contributors (besides our point man) to make this thing work out for the good of all. We've already got myself and Dave.

Depending on how this U.S. list turns out, why not continue shipping? Europe next, after the last U.S. contributor. The cost for First Class International is about $10 bucks. (only no insurance) Just mark as a gift, with a description of 'LED Flashlights', with a low value. ($15)

Since Zom-B is the first one wanting to comit, I say put him down as a contributor. The 1st person after the U.S. list...
Jay

Looks like this is progressing nicelly.

Zom-B, very good idea about the second reference laser. That would eliminate temperature very efficiently! It would definitelly be worth having a laser dedicated just for this. That is, as long as temperature effects efficiency of both in the same way..


Anyway, i wouldn't mind getting on the EU list. I couldn't possibly recieve it straight from the US myself, because our anal customs would try to charge me for it...  ;D  But once it's in EU, this problem is gone. So, count me in.

Kenom will be collecting the money when the list is done. This automatically makes Kenom the organizer of the list, and who has paid.

Kenom, sounds like we already have 4 potential contributors!

U.S.:
jayrob
daguin

Then Europe:
Zom-B
IgorT

Let's see some more people get in on this! You out there electron? We know you just got an awesome meter...
Jay

Sorry Zom-b, I may be a bit confused here, but I don't seem to understand how that solves the problem.

My concern was not about changes in ambient temp afterwards, but the fact that temperature will affect what you're considering your reference laser. IE, you assume the laser you're sent is putting out 100mW, but that may not be true. If the reference laser is run in even slightly different environments, it can cause slight variations in its output. Nothing huge, but enough to add a significant margin of error.

Am I looking at this right, or did I get confused in the details? :-/