Pman
0
- Joined
- Nov 28, 2012
- Messages
- 4,441
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- 113
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.
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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