NITROX CERTIFICATION PROTOCOLS - REAL WORLD

[Wibble]

"So it's bleeding obvious" What does that mean?

Isn't that bleeding obvious?

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But just in case...

The problem with labeling is people miss-read the labels. If you mark the oxygen percentage with one decimal place -- even if 0 -- and append a % then it's clear. 32.2%

If you mark the date in letters for the month it cannot be confused with the oxygen nor MOD. 26-Oct (or Oct 25 -- even clearer than the confusing 25/10 and 10/25)

If you suffix the MOD (Maximum Operating Depth) with 'm' or 'ft' then it's clear it's a unit of length. 33m / 108ft

Hope that's unambiguously self-evident?

 

[AfterDark]

I arrive early, and leisurely test and label all the tanks at the back of my car.



Yes it can. If your tank was hot filled the reading will differ from what it will show when cold, as most shop analyzers are calibrated with a cold tank. Or in some cases just calibrated with ambient air which add humidity as an additional calibration air. Add in the fact that labels can and do get misplaced. As such in tech diving we test every tank the day of the dive.

I'm more concerned about the tank pressure changes post fill. We all have our own concerns and what you posted isn't one of mine since I fill my own.

 

[tursiops]

The analyzer on the Den Laman/Sand Dollar Pier on Bonaire is set at 20.3 or 20.4. I have had several people ask me why it is not set at 20.9, @tursiops has nicely supplied the answer.

Cool.
The public analyzers next door at Buddy Dive have a CAL button which you push and the analyzer assumes that whatever gas you are seeing is 20.9. That means if you press it with ambient air going in you are doing a poor calibration. One needs to attach a tank of air (dry!) to it to do the CAL function.

 

[360GUY]

They have different dive trips, going to different areas. A NITROX dive is usually $10-$20, on top of the cost of the dive.

 

[Bearded Diver]

Thanks

 

[BRT]

One question. Can I CALIBRATE my analyzer with any 02 tank on the boat -- before I test my EANx tank?

One thing you don't want to do is calibrate the O2 sensor between tanks of nitrox. You will get bad readings because the sensor will reset to accepting a high O2 level as 20.9%

 

[tursiops]

One thing you don't want to do is calibrate the O2 sensor between tanks of nitrox. You will get bad readings because the sensor will reset to accepting a high O2 level as 20.9%

Depends on the analyzer.

 

[360GUY]

"One thing you don't want to do is calibrate the O2 sensor between tanks of nitrox"

Not sure what this means. Are you saying for example, I'm helping two friends test their EANx tanks. I shouldn't RE-calibrate between testing? In other words, calibrate my device, then do all the testing my heart desires, foregoing any RE-calibration???

If that's the case - doesn't make sense. It might be a waste of time, but how could RE-CALIBRATING my device, between tank-testing, be negative in any way?

 

[tursiops]

"One thing you don't want to do is calibrate the O2 sensor between tanks of nitrox"

Not sure what this means. Are you saying for example, I'm helping two friends test their EANx tanks. I shouldn't RE-calibrate between testing? In other words, calibrate my device, then do all the testing my heart desires, foregoing any RE-calibration???

If that's the case - doesn't make sense. It might be a waste of time, but how could RE-CALIBRATING my device, between tank-testing, be negative in any way?

I think he means recalibrating using a tank of oxygen, and using an analyzer that auto-calibrates to 20.9.
I hope he means that, otherwise his post is meaningless!

 

[360GUY]

Ok...Can someone please help me with this. WHY is it necessary to calibrate at all? Won't holding it to my EANx tank provide me with an accurate reading, of the percentage of O2, in that particular tank? Provided of course, the analyzer is functioning properly and its batteries are fine. Isn't my Analox O2Ell specifically designed to analyze the percentage of oxygen, present in any device I analyze? Do I have to "teach" my analyzer, what oxygen is, each time I use it?

My mother said over and over again, MECHANICAL ENGINEERING. Why didn't I listen?