What Nitrox Calculations do you use?

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citykid

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Do you have any easy to remember calculations? Or do you use an Ocean X calculator (wheel)?
 
citykid:
Do you have any easy to remember calculations? Or do you use an Ocean X calculator (wheel)?



For what? MOD, EAD, PO2?

The easiest thing to remember is to bring your tables or your computer :wink:

That said, If you look at the various formulas, and try to understand why they are what they are (rather than just accepting it) you'll have better luck remembering them. the 33 that shows up in almost every one of them is 1ATM in sea water.

But if you aren't studying for a test, you'd be best to stick with your tables.
 
I determine my mix based on where I'll be diving, calculating a MOD that would give a max PO2 of 1.4 ata. Then, I calculate my EAD for the MOD and determine my max bottom time from the air tables. I set my computer as well, but always remember my calculations. My computer just makes those multi-level dives a LOT easier. I also determine a "safety window" with a max PO2 of 1.5 ata, and determine what my emergency max depth would be if I had to descend below the planned depth.
 
Here are some of them:
PO2= ATAxfo2
MOD= po2/fo2-1x33
Best Mix=po2/ATA
EAD=1.0-fo2/.79(d+33)-33

I assume you know how to calculate FSW & ATA, but just in case:
FSW=ATA-1x33
ATA=FSW/33+1

Keep in mind: You also need to know how to calculate your CNS%, which should be on your tables.
 
citykid:
Do you have any easy to remember calculations? Or do you use an Ocean X calculator (wheel)?

For rec diving, there are a couple that you'll use all the time:

Given a particular mix, you can determine the MOD (Maximum Operating Depth).

Given an MOD, you can detemine the optimum mix.

There are others, but these are the most common. you'll cover all this in your Nitrox class.

Terry
 
Metric makes them nice and easy with 10m == 1 bar and so on.

Tend to be able to do the numbers in my head to calculate MoD and the PPO2

I dont actually have nitrox tables yet so just use computer (and apparently EAD will not work on my agencies tables).
 
citykid:
Do you have any easy to remember calculations? Or do you use an Ocean X calculator (wheel)?

Are you nitrox certified?
 
citykid:
Do you have any easy to remember calculations? Or do you use an Ocean X calculator (wheel)?

All you really have to remember is Dalton's law and Boyle's law and some algebra. All the basic formulas can be derived from that. It makes good sense to ensure you actually understand Dalton's law rather than just memorizing formulas. I don't know what an Ocean X calculator (wheel) is, but I can't imagine there's any particular need for such a thing.
 
i have no idea what the question is
 
https://www.shearwater.com/products/swift/

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