Lost Yooper
Guest
Welcome back Roakey. Do we get a trip report on the Cave Diving list? 
Mike
Mike
All about Oxygen O2 Analyzers, including DIY
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Warhammer
Guest
I have a question for those of you that have the El Cheapo. What exactly is the phone jack for? Does the 02 sensor have a phone plug end on it? Or are they hard wiring the connector to the sensor and then using it as a means of disconnecting the sensor. I can't tell from the pictures of the sensor that I've found.
Reason I ask is that I'd like to build my own, but use a PCB to place all the components on instead of just soldering wires between them. And use a water tight case. So I'd rather use whatever connector the sensor has and connect it directly to the PCB.
Reason I ask is that I'd like to build my own, but use a PCB to place all the components on instead of just soldering wires between them. And use a water tight case. So I'd rather use whatever connector the sensor has and connect it directly to the PCB.
Hammer,
The sensor and case both have mini-jack connectors. Oxy-cheq offers a coiled cord for an additional nominal cost. T recommend this opton because it makes storing easier and keeps everything much neater.
The kit is excellent. The only tricky part is that the PCB components are surface mount. So you need to have a deft touch when removing and attaching the wiring and components.
Most of the labor goes into cutting the mounting hole in the case.
I am very pleased with my analyser. Worthwile investment.
DSAO
The sensor and case both have mini-jack connectors. Oxy-cheq offers a coiled cord for an additional nominal cost. T recommend this opton because it makes storing easier and keeps everything much neater.
The kit is excellent. The only tricky part is that the PCB components are surface mount. So you need to have a deft touch when removing and attaching the wiring and components.
Most of the labor goes into cutting the mounting hole in the case.
I am very pleased with my analyser. Worthwile investment.
DSAO
You can get different sensors (from oxychek) that have different connectors but the phono plug works great.
Basically the analyzer is just a volt meter with a very narrow range specific to the sensor and with an adjustable potentiometer. The El cheapo kit includes a linear pot that makes adjustment very easy.
As for the cas being water tight...may I suggest just putting your analyzer into a pelican (or similar) case along with the sensor and flow adapter. These items need to be protected from moisture as well and the sensor is much more costly and in need of protection that the VOM ciruitry. If you build your VOM in a water proof case how are you going to protect the sensor?
Warhammer
Guest
Water tight case.....What I had in mind was to enclose the sensor in the case and make it water tight. Then just use a piece of tubing with flow restictor and a low pressure inflator connector on one end and attach it to my regs low pressure hose. I could also come up a DIN adapter so I could attach it without the regulator being attached.
When you say surface mount components, you're speaking of the LCD panel, correct? That's the only PCB that I see in the pictures. If the pot and other components are surface mount, I should be able to find a PCB mount of the same. I'd just need to identify the part. What I was going to do is build another PCB specifically for the pot, resistors, switch, and the analyzer. Then wire it to the LCD. You may be able to drill the LCD panel's solder pads in order to make soldering the wires easier, depends on whether or not there is a trace running under them, but since I haven't seen it I don't know. At any rate, I have a small home hobbiest electronic workshop and am pretty handy with a soldering iron so surface mount is not beyond my capabilities, but it is less than desirable.
Back to the mini-jack; Is it one of the jacks liked is used for headphones? If so that's no bigge. I can get PCB mount connectors for those from Digikey and/or Jameco.
Guess what I need to do is order one of the kits, then modify it to my liking.
I like the idea of putting it inside a pelican case. That may be better idea than enclosing the sensor. Although I'd still have to contend wih water while checking my tank on a liveaboard, but it's not often that I'm on a liveaboard. But I still don't like the way they have the resistors just soldered into place and wires running everywhere. I think a PCB would be alot neater.
When you say surface mount components, you're speaking of the LCD panel, correct? That's the only PCB that I see in the pictures. If the pot and other components are surface mount, I should be able to find a PCB mount of the same. I'd just need to identify the part. What I was going to do is build another PCB specifically for the pot, resistors, switch, and the analyzer. Then wire it to the LCD. You may be able to drill the LCD panel's solder pads in order to make soldering the wires easier, depends on whether or not there is a trace running under them, but since I haven't seen it I don't know. At any rate, I have a small home hobbiest electronic workshop and am pretty handy with a soldering iron so surface mount is not beyond my capabilities, but it is less than desirable.
Back to the mini-jack; Is it one of the jacks liked is used for headphones? If so that's no bigge. I can get PCB mount connectors for those from Digikey and/or Jameco.
Guess what I need to do is order one of the kits, then modify it to my liking.
I like the idea of putting it inside a pelican case. That may be better idea than enclosing the sensor. Although I'd still have to contend wih water while checking my tank on a liveaboard, but it's not often that I'm on a liveaboard. But I still don't like the way they have the resistors just soldered into place and wires running everywhere. I think a PCB would be alot neater.
The surface mount thing will not be a problem for you....
The wiring turns out to be neat...and out of sight tucked inside the case...
The case included with El Cheapo has a battery door...handy.
As for enclosing the sensor in a water tight case..... after you see it you will understand that this is not really a good idea...
The O2 at 1~2 LPM has to go somewhere!
I make sure that my pelican case doesn't have an elevated level of O2 in it before I close all the stuff up because I don't want to decrease its life.....
A sensor stored in a high O2 environment is not going to last....
The wiring turns out to be neat...and out of sight tucked inside the case...
The case included with El Cheapo has a battery door...handy.
As for enclosing the sensor in a water tight case..... after you see it you will understand that this is not really a good idea...
The O2 at 1~2 LPM has to go somewhere!
I make sure that my pelican case doesn't have an elevated level of O2 in it before I close all the stuff up because I don't want to decrease its life.....
A sensor stored in a high O2 environment is not going to last....
Warhammer
Guest
LOL! That's true. But it reminds me of a prototype vs a finished product, with the resistors soldered onto the pot and wires running from the end of a resistor to the PCB.Originally posted by Uncle Pug
The surface mount thing will not be a problem for you....
The wiring turns out to be neat...and out of sight tucked inside the case...
If I could get ahold of schematic that included the circuitry for all the components, including the LCD, I'd just build a complete PCB from scratch. But that would probably be more trouble than it would be worth. Basically all they are doing with the resistors and pot is removing a resistor and placing pot in it's place. With one from scratch you could just include the pot in the design.
That's true, didn't think about that. Especially if it's water tight, sense it would also be pretty air tight making for a possible show. LOL! Thanks for pointing out the error of my way.
I noticed that they also sell a cap for the sensor that is suppose to protect it from exposure when not in use. That would probably be a very good idea as well.
The Chairman
Chairman of the Board
Speaking of "splash proof" oxy checkers... check out their new product...
http://oxycheq.com/Expedition_nn4.html
http://oxycheq.com/Expedition_nn4.html
Warhammer
Guest
I saw that unit, NetDoc, it looks nice.
While we're on the subject of analyzers, anyone here have one of the Abyss OxySpy O2 Analysers? Those look like the ticket as well. They are higher, but still cheaper than some.
While we're on the subject of analyzers, anyone here have one of the Abyss OxySpy O2 Analysers? Those look like the ticket as well. They are higher, but still cheaper than some.
I get the impression that Warhammer *needs* to do more than just purchase a ready made unit.....
In fact I'll wager he would make the resistors, capacitors and LCD himself if he could....
That said......
what's up with buyin a *high tech sensor saver* (plumbing fitting) when you could use a ziplock sandwich bag?????
Or even better yet ....just throw it in the pelican box....
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