FieldmaxII + PM3 High-Sensitivity Thermopile Sensor

[mccarrot]

Today the mailman brought me 2 small squared boxes from the United states of America .

I did had to pay the mailman 110 Europa for customs , but I knew this before bought the toys.

I opened the first box and I found a Coherent FieldmaxII from Laserben, just as he described, in perfect condition only the batterycover is missing.

It was pleasent doing business with laserben.
After the payment to Laserben received a trackingnumber from him and two days later it was on it way to europe.

Back to the 2nd box, in this box I Found the Molectron PM3 High sensitivity sensor. Laserben tipped me for this sensor when I asked him for a sensor.
This sensor got a minimum power of 500uW and 50uW resolution. The maximum continuous power is 2W.
With this sensor I can measure my lasers and also use it as MPE measurements.

I did found something strange looking at the sensor, when I look in the sensor hole a can see the gray sensor surface, but around it there is the similar paint on the aluminium case.

Is this normal?

[sugeek]

Today the mailman brought me 2 small squared boxes from the United states of America .

I did had to pay the mailman 110 Europa for customs , but I knew this before bought the toys.

I opened the first box and I found a Coherent FieldmaxII from Laserben, just as he described, in perfect condition only the batterycover is missing.

It was pleasent doing business with laserben.
After the payment to Laserben received a trackingnumber from him and two days later it was on it way to europe.

Back to the 2nd box, in this box I Found the Molectron PM3 High sensitivity sensor. Laserben tipped me for this sensor when I asked him for a sensor.
This sensor got a minimum power of 500uW and 50uW resolution. The maximum continuous power is 2W.
With this sensor I can measure my lasers and also use it as MPE measurements.

I did found something strange looking at the sensor, when I look in the sensor hole a can see the gray sensor surface, but around it there is the similar paint on the aluminum case.

Is this normal?

The PM3 is a nice head (Coherent bought molectron so same thing as a coherent sensor). The surface is a different coating, I assume these all came from junktronics so they were probably in a bin full of goodies and got scratched. I can probably get you a battery cover in the next few weeks if you want one. Another thing I have not tested it but click the AREA button that gives you the average power over the entire sensor, I have not done the math yet but that screamed MPE to me. I read a bit on it and I guess it was for higher powered lasers, I wish Coherent would reply to me regarding having a demonstration at PaCoLEM II so I could pick their brains!

-Adam

[mccarrot]

When you press the program button and next the area button you can enter the beam diameter in mm, after this the meter will give you mw/cm^2.

To do MPE calculations you put a cover in front of the sensor with a 7mm hole in it. You set the area to 7mm and the meter will give you the mw/cm^2 reading

With a static beam the MPE is 2,5mw/cm2
With a scanned beam the MPE is 10mw/cm2
and with 10XMPE the MPE is 100mw/cm2

Do you think the coating is normal, or did someone just painted it to cover scratches?

[drlava]

It appears someone has painted the surface to cover scratches or burn marks, it's clearly not a factory job. Because the calibration data for the sensor surface is contained in the head's plug, you are going to want to MAKE SURE the calibration has not been significantly altered with this fresh paint coat expecially if you plan on using it for MPE calculation.

Other than that, looks good.

[daedal]

Well... there is something weird about that head... I have a PM3 and the entire front has the same coating as the inside. all the way to about 1mm along the side as well. It's a damn good coating too... unfortunately I've got a couple scratches on the front (not the detector itself) from being accidentally knocked into other items.

So... take a look here:
http://www.coherent.com/Lasers/index...id=996&loc=830

And here:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=350242698528 (4th picture)

That's what I mean by the front having a coating of the same material. It's odd that yours is shiny. Even more odd that it seems like it was scraped off!

Can you take a picture of the back of the sensor?

--DDL

[Laser Ben]

I would guess that coating is designed for a specific UV wavelength.

PS: I have been gone for the week because we lost out Internet last saturday. I am posting this from my phone.

[mccarrot]

So I can possibly be scammed by Action Systems

http://shop.ebay.com/merchant/actionsystems

During the purchase I have been told it was in perfect working condition.
Now it seems someone may have painted the sensor to cover up scratches.

As the original coating is important for accurate measurements I'm very disappointed. Here goes $400 down the drain.

Is there anything I can do or with the PM3 or with the seller.

I'm afraid when I send this painted sensor to Coherent for calibration they will reject it.

Here are some more pictures of the head.

[Laser Ben]

Interesting, I would still send it into Coherent and hve them take a look, that very well could be a coating applied by them to make it easyier for the detector to absorb a certain wavelength which appearing reflective to other wavelengths. Worst they could do is say that cannot do work on it and send it back.

[mccarrot]

I have send some photo's to Coherent and asked if they can still calibrate it after the paint job, and they told me calibration is still possible.

calibration costs €180, - ex.19% fat, and ex €25,- shipping. so this will cost me €240,- extra.

Damn expensive toys...

I'm trying to get some money back of this from the reseller, because he sold id as it was in perfect condition. In perfect condition I wouldn't care the calibration was over date. But now, calibration can be way off.

[allthatwhichis]

I would file a Paypal or credit card claim for mis-represented item...