O2 analyzer question

[PharmDMark]

I have just finished assembling the El Cheapo analyzer for Oxycheq, but I've run into a problem with the BC adaptor/flow restrictor attachment to the O2 sensor. I was not sent the part which threads onto the external teledyne sensor. So far my attempts to reach Oxycheq have been unsuccessful, and anyway I think I can easily make my own threaded adaptor using a brass fitting from the hardware store.

I just need to know if there should be an airtight seal against the sensor, or should air be allowed to escape in a way that doesn't put all the air pressure into the sensor (small hole in the brass fitting). It makes more sense if the air is allowed to flow past the sensor, not just forced into it, but I want to know for sure.

Hopefully, this makes sense to someone:huh:

 

[rjack321]

Don't pressurize the sensor, you just need a slight stream of gas past it. The membranes are tough but not meant to take pressure - and it will mess up your readings since the sensor reads the partial pressure of O2. Higher pressure will mean higher ppO2s.

 

[ageddiver]

I've always used the large blue T adapter and that works fine. I can get accurate readings by holding it over the tank outlet with a slow bleed, or even directly from the second stage mouthpiece. All you have to do is put a steady flow of the test gas past the sensor. Try it on a previously analyzed cylinder and it'll make you more confident. Pressurizing the sensor is not good.

 

[mirrocraft]

you call this a cheapy how much to build im in the market for one but i just dont have the money to spend

 

[onfloat]

what?

 

[ClayJar]

mirrocraft: For your enlightenment, may I present the El Cheapo II.

 

[mikerault]

I found a brand new O2 meter with all connectors, hoses and adapters for 130 bucks on Ebay...now why should I build one?

Mike

 

[SDAnderson]

I found a brand new O2 meter with all connectors, hoses and adapters for 130 bucks on Ebay...now why should I build one?

Mike

1. My theoretical understanding of how the device actually works was enhanced by the hands-on assembly experience.
2. The assembly process itself provided a couple of hours of entertainment on a cold winter night.
3. I usually find self-satisfaction when I'm able to build something instead of buy it.
4. If cheap is your only criteria, expect to get what you pay for.

YRMV.

 

[ClayJar]

As it would be about the same either way, why should you build one? Well, as it would be about the same either way, why shouldn't you build one? Guess it's comes down to personal preference.

I'm going to build mine myself, as I'll be able to incorporate a couple design features that are completely frivolous and uneccesary. Of course, those features will be the ones that make me smile when I'm using my analyzer on a boat crowded with students. Then again, I always *have* been somewhat looney.

 

[cummings66]

what?

English is not Mirrorcraft's native language, so you need to insert the punctuation and read it a few times to make sense of it.

Words are easy, but fitting them in a sentence is hard for non native persons.