Please dumb this down for me! PPO and ATA explain

[Hallmac]

I do need it explain to me in a Dick and Jane fashion! See Dick run!! thanks...

Jane is the oxygen part in the gas mixture.
Dick is the pressure. or ATA

The more Dick presses down on Jane the hotter she gets. Above 1.4 times the pressure Jane will starts getting hot and is not real happy about playing nice. Above 1.6 she is so hot she is afraid she will pass out.



Oxygen is the fuel for the body, give it too much fuel, or not enough and it quits running. It has to have just the right amount to run efficiently. Below 0.20 the body starves. Above 1.6 it over revs and blows the motor.

 

[boulderjohn]

I think I am going for ultimate simplicity here so that you can deal with rough estimates.

With sea water, use these depths for multipliers:

33 = 2
66 = 3
99 = 4
132 = 5
165 = 6
198 = 7

Multiply that by the percentage of O2 in the gas you are breathing, and you have the partial pressure of oxygen in the mix you are breathing under the pressure of that depth.

If you are breathing air at 132 feet, your PPO2 is 5 X .21 = 1.05. That is quite safe.

If you are breathing nitrox with 40% O2, then your PPO2 is 5 X .40 = 2.0. That is well above the 1.4 level considered to be safe, and you would be very much at risk for oxygen toxicity.

 

[Tigerman]

Pressures while diving is just so much easier in metric

 

[Teamcasa]

Pressures while diving is just so much easier in metric

The pressure remains the same with either method of calculation.

 

[Tigerman]

The pressure remains the same with either method of calculation.

But the numbers is WAY easier..
Base-10 makes much nicer numbers..

 

[boulderjohn]

The pressure remains the same with either method of calculation.

Yeah, but he's right.

Back when I was preparing for my DM physics exam, I chose the metric options for the calculations because they were so easy. Then I took the exam and the examiner told me I had to do them in imperial. What a pain!

 

[Teamcasa]

But the numbers is WAY easier..
Base-10 makes much nicer numbers..

True, I was just feeling a little Walteristic

 

[Blackwood]

But the numbers is WAY easier..
Base-10 makes much nicer numbers..

... I'm not sure if that was a joke or not, but metric or imperial has nothing to do with base-10.

Or does a full high pressure tank read 100101100 BAR (example being base-2) on your SPG?

 

[Tigerman]

... I'm not sure if that was a joke or not, but metric or imperial has nothing to do with base-10.

Or are your does a full high pressure tank read 110101110010 PSI (example being base-2) on your SPG

It was a kinda geeky joke refencing to the fact that metric is based on 10ths and if you work in metric, the same will apply to pressure and depth..
10mm to a centimeter, 10 cm to a decimeter, 10 decimeters to a meter..
Coincidentally(?) 10 meters to 1 ATM..

And since im metric, I work in bar so my spg would read 11100110 on a full tank in binary..

 

[Blackwood]

It was a kinda geeky joke refencing to the fact that metric is based on 10ths and if you work in metric, the same will apply to pressure and depth..
10mm to a centimeter, 10 cm to a decimeter, 10 decimeters to a meter..
Coincidentally(?) 10 meters to 1 ATM..

Yah, I know. That makes one or two operations a little bit easier (move the decimal point left or right), but in general the math is extremely simple.

Besides, when I'm planning dive/running numbers, it's never done in increments of 10m. Rather, I go in 10 foot increments, and it's extremely easy to consider every 10 feet to be about 0.3ATM. Similarly, most people who use metric units plan dives in 3m intervals, no (I've never seen a metric ascent schedule going from 40 to 30 to 20 to 10 to the surface, for example)? So you know that every 3m is about 0.3BAR.

And since im metric, I work in bar so my spg would read 11100110 on a full tank in binary..

haha yah I fixed that before you posted (though assuming 300 BAR, not 230 BAR).