YDI Oxygen Analyzer

[kidspot]

Well I just finished building my first O2 analyzer - got the kit from RC Dive. It took 4 hours at work in between customers. If anyone's interested - here's my "review" of the process and pictures http://www.kidspot.org/personal/scuba/o2/o2_1.html

Aloha, Tim

 

[JeffG]

Well I just finished building my first O2 analyzer - got the kit from RC Dive. It took 4 hours at work in between customers. If anyone's interested - here's my "review" of the process and pictures http://www.kidspot.org/personal/scubaboard/o2/o2_1.html

Aloha, Tim

Looks very similar to the El-Cheapo II by Oxycheq. (I put one of those together)


Nice job BTW

 

[kidspot]

Thanks JeffG - from what I understand they are virtually identical except for the sensors Teladyne vs. AI ...

 

[TomP]

Well I just finished building my first O2 analyzer - got the kit from RC Dive. It took 4 hours at work in between customers. If anyone's interested - here's my "review" of the process and pictures http://www.kidspot.org/personal/scuba/o2/o2_1.html

Aloha, Tim

Nice job Tim. I built an El Cheapo II [or EC2 as Patrick at Oxycheq calls it]. I had a lot of fun removing the R3 surface mount resistor but otherwise it was an easy and fun project. All of these are pretty much based on the plans from Vance Harlow's Oxygen Hacker book.

 

[diverrick]

Way cool dude!! I want one. But I know what my wife will say. (she's the boss you know). " they always have one at the dive shops, so why would you pay for one?" "plus you'll have to pack it every time we travel" Ad nauseum.....
That would be a cool project to do. and useful as well. ..... Maybe I won't tell her? No bad idea, Bad, Bad, Sorry.

 

[plankspanker]

Looks like you did a great job. $90 bucks and a few hours work is a hell of a deal. Thanks for posting the pictures on your site as well.

 

[kidspot]

Diverrick - I tested it at the LDS today against theirs ... not a fair test though as it appears the one they had was "on the fritz" today ... giving readings from 24-54% lol ... time for a new one I guess. Mine held steady at 37% for a 36.5% blend ...see, a good reason to have your own ... does that help at all? You want to be as safe as possible so you are around and healthy to be a good husband ...

TomP - removing the resistor was interesting because it was so small - I just kept "flicking" at it with the hot iron till it went flying ... seemed to work

Aloha, Tim

 

[Wayward Son]

Why have your own? I do not, just yet, but eventually will.

The shop may only have one analyzer (my LDS has 3 taht I know of, not all will), and as noted, it may choose the day you need it to crap out.

Besides, accurate analisys is a matter of potential life & death. A 2nd opinion (menaing a 2nd analyzer) provides that. Redundancy for safety. Plus, if you happen to buy fills from a shop you don't know & trust, you have your very own gizmo to check the tanks with.

$90 to make your own? Not bad at all. Looks good, too.

 

[TomP]

Mine held steady at 37% for a 36.5% blend ...

Aloha, Tim

Tim,
You may be even closer than you think. From the picture it looks like you calibrated with the bare sensor in ambient air. Temperature and humidity play a role here and 20.9 is the right setting for cool dry air but at say 30% relative humidity and temp 70'sF 20.7 would be the right calibation. There's a neat little table in the Harlow book that provides the values from 10 - 100% relative humidity and from freezing to way to hot in both F and C scales. To take the guess work out of it I generally calibrate using an air filled pony bottle.

 

[kidspot]

Tim,
You may be even closer than you think. From the picture it looks like you calibrated with the bare sensor in ambient air. Temperature and humidity play a role here and 20.9 is the right setting for cool dry air but at say 30% relative humidity and temp 70'sF 20.7 would be the right calibation. There's a neat little table in the Harlow book that provides the values from 10 - 100% relative humidity and from freezing to way to hot in both F and C scales. To take the guess work out of it I generally calibrate using an air filled pony bottle.

Actually I calibrated it from a tank to make sure it was dry air because the humidity was about 55% yesterday and I thought that might throw it off ...

I calibrated with ambient just for the photo - no scuba tanks at the t-shirt shop I was working at

Thanks for the ideas though,

Aloha, Tim