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paul1598419

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You got a great deal, Chris. Did you pay what the seller was asking for it, or did you counter-offer an amount? Can't say I've ever seen a heat sink on a thermopile like that one.
 



Alaskan

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Paul, he actually listed it at 75 dollars, they didn't know if it worked or not because they did not have the wall wart DC power supply for it. I don't think they realized it could also take 9 volt batteries inside the base. I've never seen a ball like heat sink like this either, it is very appealing to me. My thought was to buy it and if it worked find someone here who needed it, but I can't let this one go, too nice.
 

paul1598419

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I think I would have offered him $60.00 saying it would cost X amount to get it calibrated. You just never know unless you try. ;)
 

RedCowboy

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Woulda, shoulda, coulda
aint worth zips
when you're standing empty handed
only flapping your lips.
 

Alaskan

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I will once I retire, but of course it will take longer at this rate. Airplanes, lasers, boats, girls.... all too expensive. True though, you can offer 15 less, but I thought it was already priced so low I could miss out on getting it if someone else came along and bought it for 75. I hate when that happens, is has for other things.
 

RedCowboy

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I used to buy wrecked, junk, and repairable cars when I had my towing business having made a deal on the phone 1st as some people are crazy and when I rolled up and saw the deal was better than described I did not haggle I paid the man and loaded the car, no good to queer a deal being a cheapskate I agree 100%
 

paul1598419

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I will once I retire, but of course it will take longer at this rate. Airplanes, lasers, boats, girls.... all too expensive. True though, you can offer 15 less, but I thought it was already priced so low I could miss out on getting it if someone else came along and bought it for 75. I hate when that happens, is has for other things.

Yeah, if this was a new listing the extra $15.00 would not be worth the possibility of losing it to someone else. I have offered less on many items, but many had been listed for awhile when accepted. I'm glad it turned out to be a great value for you. You just never know until it arrives.
 

Alaskan

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If it makes it all better, I did offer 60 for another Coherent digital laser power meter yesterday and he accepted, was listed at 140. Now dare tell me I should have offered less than 50 :p
 

Alaskan

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I like them :) need two more to make ten. Can measure from .5 mw to 5 KW now. Don’t say it, I know.
 

Anthony P

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Since everyone is on thee subject of LPM's, what kind of meter would be required for dye laser pulse? It will fire single shots a minute or more apart (charge time for cap) and pulse duration is expected to be 10 to a few hundred nanoseconds, 590 nm.
 

BowtieGuy

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I like them :) need two more to make ten. Can measure from .5 mw to 5 KW now. Don’t say it, I know.

Chris, which of your LPM's would accurately measure low power lasers, such as <50mW or so?
 

Alaskan

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I have a Thorlabs meter for uber low power which uses a photocell, but for higher powers I have a Coherent Fieldmax II LPM with several different thermopile heads from 10 watts to 5 KW full scale. The PM10 head (10 watts full scale) can measure down to 10 mw, according to these specs:




I've measured down to 5 mw with the 10 watt head and well over 10 watts too, just takes longer for low power and the time should be reduced for higher power.

Anthony, Coherent makes sensors for short pulse high peak power. They can usually be had for a good price, sometimes better priced on ebay than the more common thermopile heads we use for CW power which are in higher demand:


I've found a few of these on ebay which have BNC connectors on the back side of the sensor, or a lead with a BNC coaxial connector on it. They can be used with an oscilloscope to measure the peak voltage produced which allows calculation of the peak power.

Here is one made by Molectron for use at 2100 nm listed as new:


Here's a used 1064 nm unit but the seller doesn't show the surface of the sensor. That's important for me to see, won't buy one without a good photo showing it:


I've yet to find one of the J## sensors made for anything but infrared, but they do exist. I guess you could buy one for IR and determine the difference at some visible wavelength if you had a known output vis laser near the wavelength you want to measure to correct your calculations against.
 
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Alaskan

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Now here's a show and tell, a rather large KTP crystal 7x7x7 mm I found on ebay cheap, came in the mail this weekend:

 




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