All about Oxygen O2 Analyzers, including DIY

[yknot]

Is there a self life on these units? Total # of tanks they can analysize or expiration time before the sensor needs to be replaced?

 

[ericfine50]

Some senors are good for 2-5 years. Depends on the sensor. I think the one that is used with the El Chepo 1 and 2 is 3 years.

Eric

 

[thethumper]

I'm maybe a bit O2 sensor 'tarded. What would I need other than the El Cheapo II to analyze 200/300 bar DIN & Yoke tanks? There are alot of extras for sale under the El Cheapo II.

Thanks,

 

[joens]

you need a sampler something to get the air from the tank to the sensor. I got the flow restrictor that plugs into the inflator hose and the other end attaches to the sensor. there are some very inexpensive that screw into the din fitting and attach to the sensor.
joens

 

[ericfine50]

You will need something to slow the flow. You can go two routes. The flow restrictor that plugs into the BC hose that flows over the sensor or the PVC style that you put in front of the valve (don't need to have a first stage on the tank.

Here are some pics:http://www.oxycheq.com/accessories.html

Look at flow restrictor or the El Cheapo Tee/DIN Connector

I know you can make some of it yourself, but I like Patrick and will buy his stuff.

Eric

 

[SDAnderson]

thethumper once bubbled...
I'm maybe a bit O2 sensor 'tarded. What would I need other than the El Cheapo II to analyze 200/300 bar DIN & Yoke tanks? There are alot of extras for sale under the El Cheapo II.

Thanks,

Required

• Flow diverter - included in the kit.
• Sensor "T" - makes life much easier. Can be used on DIN and yoke valves.
• Sensor Savor - extend the life of the critical component.

Optional

• Flow restrictor - regulate the flow of oxygen over the sensor - or with a little practice you can learn how far (not far) to crack the valve open. I bought one and it's rarely used.
• DIN connector - I don't use mine, just hold the "T" against the valve.

My .02 on O2 sensors...

Steven

 

[Padipro]

I built my analizer about 6 months ago using the info in the Oxy Hackers Guide and with help from both Oxycheq and RC. I'll tell you what, they are all very great sources of information. I talked to Patrick at Oxycheq and asked him a bunch of questions all of which he answered without hesitation, even though I had already purchased all of the parts individually from other places. It's cheaper that way then even the $89 DIY kit, I think I payed about $65 for everything and the most expensive part being the sensor. I also talked to the folks at RC because the wiring schematic on their website, and some of the instructions they have posted arn't correct and they explaned everything to me, again without hesitation. I've compaired the readings from my analizer to the readings of several dive shops name brand units and at the most there may be a .5% differance between the two.

One thing I did learn while building mine is that the unit will "Hunt" for some reading if it's turned on and the sensor is not connected. In other words it just randomly flashes through numbers. I found that to be annoying and the folks at RC said that you could solder a 1 Mohm resister across the contacts on the RCA/headphone jack to zero out the display if the sensor was not connected to the unit. It worked great.

As for the shelf life of the sensor, I was told by RC that it was about 2 years depending on the type of enviroment it was used in. It should be obvious when the sensor is nearing the end of it's useful life because you won't be able to calibrate it to your starting O2% no matter how far you rotate the calibration knob. The sensor is a fuel cell that reacts with O2 to produce a micro voltage for the meter to read. As the sensor begins to wear out it will produce less and less voltage and you won't be able to compensate enough with the calibration knob to get the meter to read correctly at the begining.

 

[yknot]

What is the biggest motivation for having your own analyzer? I recently signed up for a Nitrox class. The LDS offered it at a very attractive price along with some other training. I don't know if I will spend enough time using nitrox to justify an analyzer. Is there a fear that the equiptment where you get your fills is faulty?

 

[ericfine50]

You always want to analyze your gas, even if the store has told you it is correct. Building one is fun and you don't have to drop a ton of $$ on it. If you want to buy you - I would go with the Expidetion that Patrick sells. I think it is the best "built" unit on the market.

Eric

 

[Scubaroo]

Something that's not clear to me... the El Cheapo has the oxygen sensor internally, and the Expedition has it externally?

Shame that the Helium analyser is so expensive - it would be nice if there was a kit that allowed you to see both He and O2 content on two screens in the one box.