That's right... I said No Calibration required...

We have been playing with the OPHIR 20C-A Thermopiles...
that were on sale on eBay a while back... They were new
surplus old stock heads...
I made a deal with Kenom for a few heads and have some
more from the Kenometer Lite's I purchased from him..

They are the same ones that are used on the Kenometer Pro
and USB series...

These Heads come with a preamplifier and calibration circuit
already built into the Head and comes already Calibrated to
1mV=1mW... You don't even need to calibrate them...

All you need to do is supply a split supply and a Voltmeter..
That's all.... anything else is not really required to have
a reliable calibrated Laser Power Meter...

Here is a parts list to build a ~$100.00 LPM...
(your mileage may vary)

1) 2pc 9Volt Batteries -------- $ 4.00 (we used rechargeables)
2) 1pc SPDT toggle switch --- $ 1.00
3) 1pc DMM--------------------- $10.00
4) 1pc OHPIR 20C-A head -- $40-$100.00

We checked the current draw from the 9Volt batteries and
with no Laser input and at 1000 mW input each battery needs
to supply only 4.7mA...
The batteries will last quite a while before needing to be
changed or recharged.

You can see the simplicity of the circuit in the pics attached and it
is easy enough to follow..
The only thing that we are not sure of is the Label on one of the
heads (see Photo). It notes the Part Number as 20C-A-1-Y....
Looking at the Data Sheet we found on line...


The 20C-A means it was calibrated at customer selected wavelength...
The -1 means that the output it is 1V/1W
The -Y means that the head was calibrated for YAG 1064nm

That Part Number can only go to 4 Watts Free standing and up
to 5 Watts max with some heatsinking...
If the model number were 20C-.4-Y then... with a lot more heay
sinking the heads could read up to 20 Watts..

Even though they were calibrated for 1064nm... the calibration
seems to work well for our uses...

Now all you need to do is find some OPHIR heads...
BTW... we contacted OPHIR and in quantities of 100pc we can get
them for $250.00 USD each...

---- No Input -----------200mW Red Dilda ----- Serial Number
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