*UPDATE* Problem found LPM or Laser

Pman said:

There's kind of a long story to it all but it really is very sensitive to overall temperature and I have seen this before where it happened to be another similar red that did the same thing although the truth is most diodes will be affected by temperature pretty profoundly.
As far as freezer goes I have done it a few times with no issues. I seal it in a bag first and have everything set up and ready for a measurement. After 30 minutes in a -30F freezer it was over 250mW. Please don't panic because I ran this test. The window was clear and there isn't going to be an issue. My bet is if it stayed in overnight it would be 350mW or more. Electronics go through this kind of temperature swing all the time from shipping. My bet is most people don't bother waiting to turn on their new tv before it gets to room temp like they should. That being said, if it's 15F out I don't think anyone has all their doors and windows open waiting for the mail to arrive before shutting everything to slowly bring up the temperature

I wouldn't be returning the LPM yet for calibration because it could have been right on the money. As Alex kept testing it the overall temp probably just kept increasing so everytime it read a little lower. I would note the temperature it is ouside when it gets delivered and test it again real quick and see what it reads. I have no idea if it's already warm though where he lives so it could also read low. Both of my LPM'S agreed on the readings so it's extremely unlikely mine are wrong.
Anyone with an LPM can test the cold thing out if they want easy with a cheap ebay pen as long as there isn't condensation on any of the lenses. You can tell if there is by whether or not the beam is still sharp.
I realize it is a bit disconcerting to have such a large swing in output but that's the way it is. Pretty much everyone knows how bad 532nm is affected by the cold. Makes me wonder how sensitive 589nm is.

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Razako said:

Don't actually put a laser in the freezer or a refrigerator. Condensation can ruin it.

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InfinitusEquitas said:

That's absolutely true, but still fun to take a risk every once in a while.

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InfinitusEquitas said:

Lithium batteries are more or less fine in cold temperatures. I mean I do take out the batteries, but don't feel any special concern regarding having a battery cool down to say 20 degrees.

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InfinitusEquitas said:

Lithium batteries are more or less fine in cold temperatures. I mean I do take out the batteries, but don't feel any special concern regarding having a battery cool down to say 20 degrees.

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InfinitusEquitas said:

From personal experience, I haven't noticed any issues with my lithium batteries between roughly 0 and 110 degrees fahrenheit.

Beyond that, idk. Operating temps for our typical batteries are supposed to be -20 to 60 C, that's -4 to 140 F. I'm sure you'd experience issues if you used batteries non stop at those extreme temps long term, but short term exposure is probably not a big deal.

Some guys on CPF/BLF store their batteries in the fridge (not freezer)... maybe there is some increase in battery life, but I doubt it's worth the effort.

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Gabe said:

I always thought with my DPSS 45mW 473 "more cold more better", cuz why would it have fans to keep it cool if cool wasn't better? Turns out too much of a good thing is a bad thing, I brought it outside into my workshop on a cold winter night, thinking "oh boy it's gonna be so bright!", but I didn't have a space heater in there yet so it was way too cold and that really misaligned the crystals. I was freaking out because I had bumped when it was on the healing bench, I thought I had ruined the alignment and would have to send it to ultimatekaiser for realignment. But all it needed was some warming up to room temperature and it worked out fine. Now that I think about it I was lucky I didn't get any condensation on the crystals. But in regards to temperature, at least some DPSS lasers will bounce back from -25°C temperature nicely. Cant safely say the same for all lasers, so always best to keep your lasers out of extreme environments.

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