EAD Calculation Query

[gingerstu]

Hi Guys,

Currently going through the course material for the PADI Basic Nitrox course and am stumped by this question:

EAD = (1-o2%) * (D+10) / .79 - 10

o2% = 32 (as decimal 0.32)
D = 17.2m

Therefore:

EAD = (1 - 0.32) * (17.2 + 10) / .79 - 10
=>
EAD = (0.68) * (18.2) / .79 -10
(0.68) * (18.2) = 12.376
12.376 / .79 = 15.67
15.67 - 10 = 5.67m

Now if only Nitrox did yield equivalent air depth of the above! Happy days indeed. Obviously this is wrong and the correct answer is 13.4m

I have used my method on other questions and have got the correct answer. I have also done an excel spreadsheet that produces the correct answer, but everytime I do it on paper with a calculator I always end up with the above answer.

Can anyone post my deliberate mistake?

Cheers,

Stuart

[Steve Sub]

Originally Posted by gingerstu

EAD = (1 - 0.32) * (17.2 + 10) / .79 - 10
=>
EAD = (0.68) * (18.2) / .79 -10

Stuart

Might be a "user error" here...
HTH
Steve

[gingerstu]

I'm a tit! I knew it would be a simple error - woods and trees spring to mind!

I'll leave the post there so everyone can have a laugh.

I'm not convinced that 17.2 + 10 is 27.2 are sure it isnt 18.2?!!!

Will change my signature to Mathematical Genius!

Thanks Steve - incoming

[Gascan]

From your buddies point of view Danger Danger is good
Brings up the importance of both members of the dive team planning though. Errors like this are easier to spot if one of you has a different answer and unfortunately it is an easy mistake to make.

[colinicky]

I looked at the first post for 30 minutes & still couldn't spot it !
& I've got advanced nitrox deco & ccr mod1 Anybody got one of those hats with a big "D" on it ?

[gobfish1]

Originally Posted by gingerstu

Hi Guys,

Currently going through the course material for the PADI Basic Nitrox course and am stumped by this question:

EAD = (1-o2%) * (D+10) / .79 - 10

o2% = 32 (as decimal 0.32)
D = 17.2m

Therefore:

EAD = (1 - 0.32) * (17.2 + 10) / .79 - 10
=>
EAD = (0.68) * (18.2) / .79 -10
(0.68) * (18.2) = 12.376
12.376 / .79 = 15.67
15.67 - 10 = 5.67m

Now if only Nitrox did yield equivalent air depth of the above! Happy days indeed. Obviously this is wrong and the correct answer is 13.4m

I have used my method on other questions and have got the correct answer. I have also done an excel spreadsheet that produces the correct answer, but everytime I do it on paper with a calculator I always end up with the above answer.

Can anyone post my deliberate mistake?

Cheers,

Stuart

(1-o2%) / .79 * (d+1o ) - 10 = EAD

mix 32% depth dive 17.2m

1-.32= .68 / .79 *27.2 - 10 =13.41 (14m)

[Ferg3333]

Originally Posted by colinicky

I looked at the first post for 30 minutes & still couldn't spot it !
& I've got advanced nitrox deco & ccr mod1 Anybody got one of those hats with a big "D" on it ?

Just get a big sheets of paper roll it into a cone and give me 100 lines

[principia]

Originally Posted by Ferg3333

Just get a big sheets of paper roll it into a cone and give me 100 lines

Sounds like my student days

J

[uwila]

Sounds like you were narked when you tried to work that one out

Since you made me laugh, and as a consolation, have a green to offset the public humiliation

[onthetrain]

Originally Posted by uwila

Sounds like you were narked when you tried to work that one out

Since you made me laugh, and as a consolation, have a green to offset the public humiliation

Never mind all that. Are you going to do a trip report on your course last week?????