Calculating MOD with EANx

[decompression]

I love standardized gases......this makes my brain hurt!

 

[Insta-Gator]

instagator -- see I do not understand that. -- :x lucikly I do not have to do any real abstract math in my job. The back seat only holds four.. five if you stack em

If you can pass the course (you'll miss two questions without knowing the math) just be sure to use the tables and set your computer properly. In reality, if you ALWAYS dove EAN32 and set your computer accordingly, you won't have to know the math any more than you do for diving air (21%)

 

[fugly]

There is an app for EAN.

 

[JohnN]

There is an app for EAN.

The math isn't complicated. No reason not to understand what it is and how the calculation works

 

[mathauck0814]

Simple math here folks:

Desired PP02 / F02 = MOD

Example, if my desired max PP02 is 1.4 and I have 32%

1.4 / .32 = 4.375 ATA

Convert ATA to Feet

ATA * 33 - 33

4.375 * 33 - 33

144.375 - 33

111.375 feet

 

[miked]

I agree that having a table/chart is the simplest way to go. That said, the formulas are , IMHO, needlessly complicated, in that they attempt to get the result in "one big bite".
For the math anxious in the group, I'd suggest a 3 stage approach-'smaller bites, if you will:

Stage 1: get the number of "atmospheres" that will produce your max PPo2:

Atmospheres = PPo2/Fo2 (your 1.4 or1.6 or whatever, divided by the o2 percent of your mix)


Stage 2: subtract 1 from that result, to remove the pressure of the. well the actual atmosphere.

Stage 3: multiply that result times 33 (for feet) or 10 (for meters).



Example: find the MOD for a 1.4 PPo2, and a 32% mix

Stage 1: 1.4/.32 = 4.375

Stage 2: 4.375-1=3.375, the number of atmospheres of water pressure at the MOD

Stage: 3.375 *33=111.375 MOD for a 32% mix.

YES, it is longer, and 3 steps,and mathematically, the other formulas incorporate all this math into a single formula, but as I said, IMHO, the "smaller bites" may be easier to digest.
Good luck with whichever method you use!

 

[HowardE]

Here's a spreadsheet with 1.4 and 1.6... If for some reason you want 1.5, it's in the middle... But as others have said, the math is straightforward.

 

[rhwestfall]

easy

excel spreadsheet
View attachment EAN-MOD-EAD Calculator.xlsx


or....

excel spreadsheet with pulldowns



View attachment MOD-EAD Calculator with pull down.xls

this is used at your own risk.....

 

[C P]

For a 1.4 exposure use: 46.2 divided by O2 % - 33 = MOD
1.6 52.8 divided by O2 % -33 = MOD

 

[Insta-Gator]

y'all makin' my head hurt.