Analyzing your own nitrox tanks

[34109411]

I took the PADI nitrox course this week, and it was made very clear that you always analyze your own tanks before using them. Then I was told that the analyzers are very expensive and there is usually one around to use.

The next day I got on the boat with the same shop (my instructor was on board). I used their analyzer and got a very different reading from what was marked on the tanks. A crew member came to help me and it turned out the analyzer was drifting after being calibrated. After we tried a few times and got varying readings approaching what the markings said, she told me that it was okay to use the percent marked on the tank.

That night I met a local guide for a dive and she provided the nitrox tanks. She didn't have an analyzer so I went with what she had marked on the tanks.

It seems like many of the "rules" I've been taught in scuba courses tend to be more "guidelines" when I get out in the real world. Is this one of them? What are people's practices as far as analyzing your own tanks?

don't trust anyone. analyse your own tanks. a analyser is not that expensive. Don't risk you life by not spending money on something that will save your life.

When the course is done you are on your own to make decisions don't let the others do it for you for the sake of your life.

Be safe

 

[autrichon gris]

I have an analyzer linked to my Ratio Ix3m2, and it works perfectly well. It's exclusive for Ratio computers (check their website if interested).
Once you have measured the % of oxy, just click to set to the mix 1, or 2 ... and you are ready to go diving with the right mix in your computer.

 

[lizardland]

Analysers are so cheap that I don't get why most people who dive regularly don't own one. You can even make one for next to nothing. There are tons of DIY designs out there. And with the cost of Arduinos and ESP32's these days you barely have to do anything more complicated than plugging a few wires together. An Arduino Nano, a display, an ADS1115, half a dozen jumper wires and about 30 lines of code. Probably £15 at the most from Ebay. I keep meaning to put mine up on GitHub.

The cell is the biggest investment but even then it's what? £30 a year? Or free if you dive a rebreather and changing cells regularly (or know someone who does).

 

[BRT]

Both of you are missing the point.
If the shop has a dedicated tank that is kept where the analyzers are hanging on the wall - marked with 20.9% - then that tank can be trusted to be air and only air. It eliminates the opportunity for it to be a tank that has any blend other than air in it.

Use the big free tank. It always has air in it. Any tank that has been filled could have something else.

 

[lizardland]

Use the big free tank. It always has air in it. Any tank that has been filled could have something else.

Exactly. Assuming that a 20 year old on minimum wage cannot find a way to completely screw up the most robust, most failsafe gas filling system on the planet is a stretch.

 

[tallman]

I have an analyzer linked to my Ratio Ix3m2, and it works perfectly well. It's exclusive for Ratio computers (check their website if interested).
Once you have measured the % of oxy, just click to set to the mix 1, or 2 ... and you are ready to go diving with the right mix in your computer.

Do you have to use Ratios sensors when replacing or can you use others?

 

[NothingClever]

Not analyzing one’s own gas is just dorky.

I’d trust @VsubT or @Divin'Papaw to analyze my gas but I also trust they’d both look at me with a furrowed brow if I didn’t grab an analyzer to confirm.

 

[Divin'Papaw]

Not analyzing one’s own gas is just dorky.

I’d trust @VsubT or @Divin'Papaw to analyze my gas but I also trust they’d both look at me with a furrowed brow if I didn’t grab an analyzer to confirm.

I wouldn't trust myself to analyze your tank!!

Joking aside, you are the one breathing your gas and therefore you should be the one analyzing it.

 

[Johnoly]

I’d trust @VsubT or @Divin'Papaw to analyze my gas

I wouldn't trust them.
They'll write the mix on a Hello Kitty sticker and then slap it on your tank !!

 

[BRT]

I wouldn't trust them.
They'll write the mix on a Hello Kitty sticker and then slap it on your tank !!

Hello Kitty, masking tape, write it on something.