Power Meter Calibration and Comparison

Kenom,

May suggest a new shipping order, I think this is the fasest way to get the laser around.

Kenom MT
Pseudonomoen137 TX
Daguin So CA
Scopeyguy So CA
Hydro So CA
Pullbangdead So CA
Jayrob N CA
DanQ N Ca
GooeyGus WA
rkcstr OH
Dr. Lava OH

Europe
Happytomato UK
ZomB Netherland
Igort EU

Let me know what you think. If you look at the map this will give the shortest down time (shipping).

Thanks

change it on up!

UK customs might also be less restrictive, than Netherlands.. The sender (DrLava) will just have to make sure to declare it as a low value item.

hmm, so my shipping bill will be for international? :O

drlava said:

hmm, so my shipping bill will be for international? :O

Click to expand...

The person being shipped TO is supposed to pay the shipping. You should pay Rkcstr for shipping from Toledo. HappyTomato should pay you for shipping it to the UK.

Peace,
dave

oh, thanks. sorry for Happy, then :-X

The lazors is on it's way to pseudo. Sent priority insured for $200

Just for reference, how much was shipping?

Priority to TX, with $200 insurance was $9.80

See attached receipt.
this did NOT need to go out priority. it could have gone by parcel post for $6.13 instead of $7.20

Sweet, less than $10, that's all I was hoping for.

I think it is high time for another update on long term laser stability. I've been running and measuring my stable long open can laser for two weeks now (306+ hours) and it still does not lead to a definite conclusion. It does reveal however, that the laser is very dependent on temperature (1mW per 2°F) and taking that into account, it also looks like the laser increased in power with an inverse exponential curve, stabilizing for 90% after the first 24hr, and only having increased less than 1mW in total (if at all).

Yeah but it's not that conclusive considering you have power readings in the same temperature range that vary by 1-3mw. You could stabalize the temperature in a closed enclosure, but I don't know if that would even solve the problem. Still all things considered you have a pretty stable laser there. I'd be willling to bet if you were to throw it on a tec, with a really large heatsink, you'd probably notice a nice stable laser.

Not sure if I should even include blu-ray readings from my LPM-1. (well, I guess it couldn't hurt)

I say this, because I have been doing comparisons with my LPM-1 vs my Coherent PM5200, and I am getting some inconsistent numbers??

I have noticed that for reds, and also for my RPL 473nm laser, that the LPM-1 is very close to my PM5200 (PM3 sensor).

But when comparing blu-ray measurements (using a multiplier with the 473nm setting), the multiplier does not hold true for different powers. Example:

On two different blu-ray lasers, using the Coherent thermal meter, I got 101mW's on one laser, and 138mW's on the other. So I found the multiplier for the 101mW laser was 2.62 for my LPM-1 on the 473nm ND filter reading.

Now, I thought that I would be able to use the same multiplier to see if it translates out to the correct reading of the second laser...

But no! In order to get to 138mW's, I had to change the multiplier to 2.49??

This is puzzling. :-?

So (looking for input), I'm guessing that if anything is out of spec., it is most likely the LPM-1, because it was not designed for 405nm. But the PM3 sensor is...
Jay

Try with the attenuator on the LPM-1 if you did not do so already, and see if the multipliers match up then.

Or contact drlava, he worked with the designer of the LPM-1

[edit]hmm according to this graph at http://www.photonlexicon.com/forums/showthread.php?p=19279 it seems to start saturating beyond 100mw, and I don't know the aperture size but if it is significantly larger than your beam diameter, then it might be that it is saturating locally, even though less than 100mW reaches the sensor. Try increasing the spot on the sensor and try again if the multipliers match.

Pseudo should have the calibration lasers on monday or tuesday at the latest. We should see pretty quickly how accurate my meters are.

Everyone could enter his complete address in the spreadsheet onthe routing tab so there will be no uncertainties where people live.