Nitrox Analysis & Labeling

Divers Ready | UTD | Dive Soft | Andy the Northern Diver

WARNING-WARNING-WARNING
THIS DISCUSSION IS BY A RECREATIONAL DIVER FOR RECREATIONAL DIVING WITHIN RECREATIONAL LIMITS

Do I Need My Own Analyzer?
How do I Label The Tank?
Where Should I Put the Tape/Label?
What About MOD on the Tape/Label?

Do I Need My Own Analyzer?

A snap answer from virtually every diver who already has one is yes...absolutely. And why is that?

You can't trust the dive shop that filled your tank [ Snark: Why are you using them then? ]
You need to be sure you're not diving some exotic mix of gas [ Snark: exotic? really? that has actually happened to you? ]
Only you are responsible for you [ Snark: Now you're talking my language ]

...All technically correct. And at the same time an incorrect risk assessment for most recreational divers.

Why is that?

Owning your own analyzer will increase the total cost of your diving equipment by 25% or more. And there are far more important items for you to own.
It is EXTREMELY rare for a dive shop to fill your tank or hand you a rented tank with anything other than air. The accidents you hear about involving "bad air" are almost always carbon monoxide or carbon dioxide...neither of which will be found with an O2 Analyzer.
It is even more rare for a tank to be accidentally filled with an O2 mix that is not either Air (21%) or something they bank (typically Nitrox 32%). Neither of those will harm you at recreational depths.
If you are really concerned, a reputable dive shop will let you use their analyzer before you leave

So a nitrox analyzer should be one of the LAST items you buy.

How Do I Label The Tank

You will need:

An O2 Analyzer
A pen or marker
Some tape or a label

Information to put on the tape/label:

(Minimum) The O2 content to a single decimal
(Recommended) Your initials
(Recommended) Date you did the analysis
(Optional) Tank Pressure [ PSI ]
(Optional) Minimum Operating Depth [ MOD ]

Where Should I Put the Tape/Label?

Under the valve handle. It protects the tape from being rubbed off and it's easy for your buddy to confirm the gas when they double check your valve is open as part of the pre-dive check.

Some people like to have the label on the opposite side of the valve handle, because it is easier to see if you are doing a gas switch. But since, we are doing a recreational dive on a single tank, we won't be doing gas switches...and...on a technical dive, you wouldn't be using this tape label to confirm the gas...there are better labels for gas switches...so I don't understand this preference.

Why is MOD optional on the analysis label?

It's not used for anything before, during or after your dive so I don't put it on my tape/labels.

But if you want it...put it on the tape. It's your tank. It's your tape. It's your dive.

MOD labels on tanks IS required if you are doing gas switches, but that wouldn't be on O2 analysis label and it would not be a recreational dive.