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MarioMaster

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Do not adjust the internal calibration unless you have a very stable laser with a known power to calibrate against. 445 diodes can vary quite a bit in power due to heat, and DPSS lasers are unstable to begin with. When I calibrate these lasers I use a 2 watt 808nm laser diode that is temperature regulated with a TEC to maintain tight regulation.


Seeing as how your peronal 1W 445 laser checks out in power, either the lens is eating a lot of power on your friend's laser or the diode was just below average from the start. These 445 diodes have a fair bit of power variation from one diode to the next.

Make sure you recharge all your batteries. Low batteries can cause huge headaches.
 
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MarioMaster

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You just said your 1 watt laser read 172mW. Something is obviously not right here. I doubt the LPM's calibration would change that much randomly.

Recharge all your batteries and give it a go again. You can always return it for repairs at no cost if it does turn out to be the meter. Radiant Electronics prides itself on always rectifying any problems.
 
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regalis

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Yobresal sells his 1.1-1.2 W running at no greater than 1.25 A. All my lasers that run at 1.2-1.3 A output more than 1.1 W with an aixiz 3- glass lens. Either the diode is underspec or the lpm miscalibrated. And yes, you CAN count that it will output >1W if the diode is up to spec AND I believe SL does not sell underspec diodes.
It belongs to the efficiency of the diode how much power they output.
High-Efficiency-Diodes (also called freaks) can output 1mW per 1mA but that is not the regular output rate.
 
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blakegriffin

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I just lpm'd my 300mw 445nm laser it said it was just above 25mw then it started to light matches and smoke plastic like a 300mw laser.
 

regalis

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Then maybe send it back to get it recalibrated...
Btw.: Are the LPM Batteries fresh?
 

blakegriffin

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If any one doesn't have any suggestions I think I might half to send it back :(
 

Elektrotechniker

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Does all the light go to the sensor at all? Im not sure if you point it at the right spot.
 

blakegriffin

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I just changed the meters batterie and my 300mw 445nm laser out put 200mw rather than 25mw so I think it is just a little of I know someone who has a lpm in los angeles and I will calibrate it to his.
 

JLSE

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Do not adjust the internal calibration unless you have a very stable laser with a known power to calibrate against. 445 diodes can vary quite a bit in power due to heat, and DPSS lasers are unstable to begin with. When I calibrate these lasers I use a 2 watt 808nm laser diode that is temperature regulated with a TEC to maintain tight regulation.


Seeing as how your peronal 1W 445 laser checks out in power, either the lens is eating a lot of power on your friend's laser or the diode was just below average from the start. These 445 diodes have a fair bit of power variation from one diode to the next.

Make sure you recharge all your batteries. Low batteries can cause huge headaches.
Perhaps the coating? Have you changed what you use? I have a list of readings I
took when I had an alpha with different wavelength lasers.. If I can find it, i'd be
happy to share.. I do recall differences in power vs wavelength, but can remember
the specifics.

I know when I did a DIY LPM, finding a suitable coating for the sensor was the hardest
part...
 

MarioMaster

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I have not changed the coating.

It seems his problems were caused by a nearly dead battery in the LPM.
 

blakegriffin

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My laser are still undergoes but that is probably because of the lasers not the lpm
 




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