IgorT customs LPM review.

[brtaman]

Well, this review has been in the works for quite a while.
*********************Warning picture intense review!!!!***************************

The LPM, is completely custom built by IgorT, so I don't think that I need to explain the high quality standards to which it was built.

Technical:

-Thermal meter
-Two Measuring Ranges: 200mW / 0.1mW resolution and 2W / 1mW resolution
-Accuracy +-2%
-Completely analog uses high precision OP-AMP circuit to amplify signal from thermal head
-Uses 9V battery
-Very nice and compact size (see pictures for size comparison)
-battery friendly (been using the same 9v Duracell batteries with quite heavy use since november!!)
-Low battery warning light

Review:

I am extremely happy with the LPM. It has shown to be very accurate (not surprising given the builder). Its small size makes it nice and portable (it fits directly into my laser suitcase, in case i need to use it in the field). I am quite fond of the design of the LPM to me it feels and looks like a professional tool, however, being the cheap bastard that I am, I opted for the cheapest case Igor could find. It has served me very well up until now and I believe it will last me quite a long time. The box even, if it was the cheapest one available, feels very sturdy and seems to me to be of great quality.

I fully recommend this product (like I do all of Igors products) to anyone looking for a quality LPM!

Size comparison shot:

For the size comparison shot included a couple of batteries of pretty standard sizes as well as a couple of lasers, to give you an idea the size.

Insides:

Action shot: (measuring a LOC Kryton Groove Build w/flexdrive@ 510ma through acrylic lens )

And one final picture.

Thanks,
brtaman

 

[jayrob]

Nice meter! Igor is the Man!

I understand that he might have another meter that he built for sale...

Someone else is going to get a good deal too!
Jay

 

[daguin]

My wife said to tell you that you take very good photographs.

I saw pictures of this when IgorT was just finishing it up. I have been jealous of you since then.

Peace,
dave

 

[lasersbee]

That is a nice looking LPM that IgorT put together... [smiley=thumbsup.gif]

Jerry

 

[IgorT]

Haha, oh my. I forgot how messy yours looks inside..   ;D

It was put together from three separate circuits, in a rush.. Hence all the wires...   :-[


The circuits are all from my first meter, which was gradually added more and more features, on separate circuits..   Since your box was so big, i just used them all for your meter, to get it done faster...

The new one has it all on one single circuit, so it's a much "cleaner" build inside.  :



Jay: I am thinking of selling my secondary "backup" meter, yes... That one looks like this. (Altho the pic shows my primary meter with a Coherent thermopile inside - i am NOT selling that!)
It's in a more expensive higher quality enclosure, runs off a single 9V and has a nice battery compartment on the back panel, as well as a 9V DC adaptor socket, for external power. The rest is the same..

I took the left picture just after finishing Brtaman's LPM, for size comparison. I call it the "MeterPile"...

 

[brtaman]

Thanks for the replies, guys!

It is definitely a great meter...daguin has every right to be jealous. (please thank your wife for me.)

 

[IgorT]

And while we're talking about LPMs...


This is what i would like to make for myself one day... I just hope i can find the time soon!

It's gonna be a handheld meter, with an external thermopile on a tripod.


I found this nice box with a battery compartment, a stand, an LCD cut-out, a slideswitch on one side and some kind of slot on the other side. I had no idea what i'd use it for, i just knew i liked it, so i bought it. This was years ago! It's been gathering dust ever since..


But now i found a nice Digital Panel Meter, that fits perfectly when "undressed", has a backlight and even a low battery warning on the LCD itself.
I can use the slide switch either for ON/OFF or as a range switch. All it needs is a nice label on the front, and a switch and zero-offset pot on top... No heavy machining will be required for this enclosure!

I will even try to make some kind of mount for the thermopile, so that i can stick it into the slot on the right side, for storing away. Then it can just slide out, and be placed on the table on it's tripod...


Another thing i would like to do is, add a photo sensor, that would automatically adjust the LCD backlight to ambient light conditions, for prolonging the battery life, by reducing the brightness of the backlight, when it's not required.... This photo sensor could be mounted in that small square area just above the LCD. Since it's at an angle it would measure the light from the direction the LCD is viewed!  



Again, this is NOT something i want to sell! I just make it for fun. Maing stuff like this is not easy! It takes a LOT of time to machine the box, in order to fit all the external parts perfectly (the handheld will actually be easier since it already has the holes). I make devices somewhat similar to these (but unrelated to lasers) at work, but they are not cheap!



What do you think about the Handheld LPM idea, guys?
I know it looks plain at this moment, but the other boxes were much plainer looking, before that simple front panel label was applied. With a label, this one is gonna look VERY nice!

 

[diachi]

I want one How much was it ? :

Very nice work IgorT as usual

 

[IgorT]

Thanks, Diachi!


Well, Brtaman's meter was more of a favor type thing.. He wanted a cheap LPM. I tried to find the cheapest way to do it. (Problem is, no matter how cheap the box, it still needs some expensive parts)... But it came out quite nice in the end.. A simple front panel label makes a lot of difference.

I just wish i could have put a battery compartment into it. It could be a little nicer then. As it is, it was only supposed to have a hole in the back panel. But i didn't want to do that, so i created a sort of battery compartment from scratch, out of plastic sheets (since i wasn't allowed to buy a proper one  ;D).. This improvised compartment is not seen in any of the pictures, it was added after the internal picture was taken. But it holds the two 9V batteries nicelly, so they don't rattle around in the box...


If it was up to me, i would have used the white enclosure, a proper battery compartment, and a voltage inverter, to make it work off one 9V battery. Then it could also work off an external 9V adaptor. (I can still do this upgrade to your meter if you want, Brtaman....)


Anyway, i have another meter, that looks the same as my main one (the one in the white box). It's meant to be a secondary backup meter (for calibration reference purposes)... I might be willing to sell it, if it should be required to get the GB money together faster... If i do, i will post it in the BST section...





This is that damned battery compartment i was "not allowed" to use.. If i knew how much more work that will cause, i would have given Brtaman a compartment for free..   :
Altho, to be honest, it's my fault he said "no" - i remembered the price incorrectly, and said 13€, while i later found out it's much cheaper, when i was buying more. The price i remembered was of another, much more complex compartment..  :-[


This battery compartment is very nice, it's a snap-in design, which means, you have to cut a hole of the right shape and size, and then just stick it in, and it stays put. It has a small edge, which covers any imperfections in the cut you make, just like all snap-in parts. As long as the imperfections are not too big for the edge to cover them, that is.. The external profile is very low - it only sticks out 1mm or so, above the panel.. Less even, than the edge of the switch next to it! It even has two labels included for battery polarity indication. You just apply the correct one into the bottom of the compartment..

The compartment can take either a 9V or two AA cells, depending on how you configure it... I have the same compartment in the bottom of my "Diode Analyzer", but there it's housing two 14500 cells..


It's parts like these, that allow you to make very professional looking devices, out of "generic" components.. If you do it right, you end up with a build that is completelly closed off and sealed, and looks good, almost factory made....

 

[jake21]

i hope im on the list for one

 

[IgorT]

Hehe, you just get the circuit, and the peripherals on wires, no box... You're gonna have to do the hard part - the box cutting and the mounting yourself....

Altho you wanted it that way.. BTW, are you gonna take the battery compartment? ;D

 

[jake21]

yup i want every thing all set up and ready to go, i just want to mount every thing in my custom box

 

[IgorT]

Ok...

That means i only have parts for one left... Not even sure if i want to sell that one.

 

[jake21]

so does that mean no meter for me ?

 

[JLSE]

What are you using for the sensor? is that also a TEC similar to a LaserBee I?

I wanted to takle making one for the fun of it some time, TEC seems to be the way to go for DIY LPM's

 

[IgorT]

so does that mean no meter for me  ?

No, it means that AFTER your kit, i only have parts for one more left. And originally i wanted to keep that one.. That's all i meant.