El Cheapo II

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Anyway, I just built my EC2 tonight. I made it a bit differently than "stock", as I mounted everything in the "back" of the case (the side with the battery compartment). Nothing is attached to the front of the case at all, so if I need or want to open it up, I don't have any annoying battery wires or anything.

I mounted the display on the top of the now-front face, with the battery door on the bottom. In the middle, all lined up left to right, I have the sensor cable jack, the switch, and the (10-turn) pot. (I figured with the cable plugged in, it and the pot would prevent accidental switch manipulation. :biggrin:) I got the whole thing to pack neatly into a Pelican 1060 case for transport.

You have to order it direct from OxyCheck ... http://www.oxycheq.com/Welcome.html
El Cheapo II

Oxygen Analyzer Kit

MSRP: $ 100 USD


DIY... Build it yourself, save $$$, and learn something!

The OxyCheq El Cheapo II is an oxygen analyzer kit. It takes about 3 hours to complete.

The "El Cheapo II" oxygen analyzer kit works as well as any commercial O2 analyzer.

The "Kit" includes all of the parts necessary to complete your own oxygen analyzer. The "Kit" also includes a brand new Teledyne R-17 Oxygen Sensor in a factory sealed bag. Detailed instructions walk you through step by step from preparing the case to soldering. Warranty does not apply to DIY.

This item is only sold directly from OxyCheq. This kit is the very first product that OxyCheq came out with.
I ordered mine 2 weeks ago, and built it last night (thanks Patrick!). I also put in a 10 turn potentiometer as they allow for much, much better calibration control. We use the exact same "pots" on our peristaltic pump drives due to the control they allow.

I have tried it with both pure O2 and pure N2 (love working at a lab) and received accurate results.

Now all I need is a flow restrictor, in line flow meter, "sensor saver", and a cap.

I am going to post a project log when my sensor unit is complete. (so all plumbed, mounted in pelican case, etc.
Edit: Took a guess and got lucky. Here's what I did.

Strapped it via the solder jumpers for DC, 200mv.
You also need to jumper it for 9v DC via J3 and J5.

R3 is still R3 it seems. I used small cutters to cut the tiny resistor so I only had to unsolder each half, not both sides at once.

There's 3 solder points for P1 - use the two outer-most.

On the 10-turn Pot, use the outer two contacts. If you put the Pot close enough, you can use the supplied resistor directly from R3 to the pot. I used a piece of heatshrink to insulate it.

The DC Input points - the longer side of the battery symbol is positive.

A fine-tip soldering iron is a must, and fine solder helps too. I used some 0.8mm.

Now I just need to pick up a longer 1/8" mini plug cord...


Anyone done the EC2 kit recently? The panel meter supplied with the one I just got has additional strapping that I'm not sure how to set - and a lot of other changes it seems.

The new/current panel meter has jumpers to select the DC voltage range:


I realize that the sensor is going to be in the low millivolt range, but I don't know if pre-selecting that will throw off the other resistors changed/added to calibrate. I'm note sure what the original meter expected as far as that goes...

Hoping that the infamous R3 is still the same. Looking at the traces it seems to be in series with the on-board calibration pot, so in theory we're basically moving it outside and adding some range, right?
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