Please dumb this down for me! PPO and ATA explain

[boulderjohn]

I don't know if you've ever had the pleasure of sitting in an advanced mathematics or statistics class with a professor who just happens to be a pedantic PhD., but sometimes the instructor, because of his or her in depth knowledge of a subject, has no clue, whatsoever, as how to present the subject matter to the student in a comprehensible manner.

Different people's minds work in different ways. This is often referred to as "learning styles." Unfortunately, most people who know something about learning styles took a workshop in which a learning style theory is presented. This leads people to think that it is as simple as the presentation they saw. In fact, there are at least 100 different formal theories on learning styles, and many contradict the others. We really don't fully understand how it works, but different people do indeed learn differently.

After a lifetime in education, I believe math is where the difference comes through the most. I once heard a theorist say that only 15% of the population is geared to learn math the way it has been traditionally presented. The problem is that the population of math instructors usually comes from that 15%, and they then use the "it worked for me" approach to teaching.

Much of traditional math instructional texts feature page after page of stacks of numbers, an approach the National Council of Teachers of Mathematics (NCTM) has been striving to change for years. Once a student begins to get the "I'm a math failure" attitude, just seeing a stack of numbers is like Turning a switch off in the head--all learning stops before it begins.

It is not about being dumb--it is about learning in a way that makes sense to you.

 

[BarryNL]

Ok, I'm still new and I would like someone to explain in examples ...Analogies help learners make these interconnections by linking new information ... easy text.

Partial Pressure of oxygen ...is it the Pressure in a tank with Partial Oxygen??

Well, PPO is pretty easy - the calculation is simply the percentage of oxygen multiplied by the absolute pressure - so, if you are at 20m you are under 3 bar of pressure (I assume you are familiar with this from your OW course?). Now, if breathing air you are breathing 21% oxygen x 3 bar of pressure = 0.21 x 3 = 0.63 bar PPO (= 0.63 ATA - for nitrox theory, bar and ATA can be considered the same).

If you need an analogy, think of a box containing 100 bricks each weighing 1kg - 21 of the bricks are red and the rest are yellow. We can say that 21% of the weight is caused by red bricks and the rest by yellow bricks - the partial weight of red bricks (PWR) is 21kg. Now, imagine you move the box to another planet where gravity is three times as strong. Now the box weighs 300 kg, of which 63 kg is due to red bricks (ok, I'm confusing mass and weight, but go with it).

 

[Teamcasa]

It is not about being dumb--it is about learning in a way that makes sense to you.

Exactly. Some people learn by hearing and not by reading information while others get the picture visually. We all need to take our own vehicle of learning down the road that helps us best get the information.

 

[GloryDayz]

Well, PPO is pretty easy - the calculation is simply the percentage of oxygen multiplied by the absolute pressure - so, if you are at 20m you are under 3 bar of pressure (I assume you are familiar with this from your OW course?). Now, if breathing air you are breathing 21% oxygen x 3 bar of pressure = 0.21 x 3 = 0.63 bar PPO (= 0.63 ATA - for nitrox theory, bar and ATA can be considered the same).

If you need an analogy, think of a box containing 100 bricks each weighing 1kg - 21 of the bricks are red and the rest are yellow. We can say that 21% of the weight is caused by red bricks and the rest by yellow bricks - the partial weight of red bricks (PWR) is 21kg. Now, imagine you move the box to another planet where gravity is three times as strong. Now the box weighs 300 kg, of which 63 kg is due to red bricks (ok, I'm confusing mass and weight, but go with it).

I know this is an 8-year-old thread, but whatever...

As I prepare my younger son for the AOW and Nitrox classes next month, the quoted reply was a great analogy that he totally understood.

As for why the "1.4" is used, without getting into the math, I just told him that through trial and error, the U.S. Navy I dove for found 1.6 = dead sailors, and 1.4 = alive sailors, ans he was just going to have to accept it.

But I had him watch some oxygen toxicity videos, then told him, simply, that more O2 = more chance of CNS. But also that more O2 = less Nitrogen. Since he understands the concept of offloading Nitrogen, it wasn't hard for him to understand how bringing less on equated to more diving and/or shorter SIs.

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[Saniflush]

Jane struggles with the maths during the divemaster briefing, get lost, and dies because she screwed up a multiplication. (I like having my characters die, it's more dramatic).

.

I do so love the Greek tragedies!

 

[Lake Hickory Scuba]

Ok, I'm still new and I would like someone to explain in examples ...Analogies help learners make these interconnections by linking new information ... easy text.

Partial Pressure of oxygen ...is it the Pressure in a tank with Partial Oxygen??
ATA 1.2 to 1.6 Atomospheres?? Like is this the depth pressure??
this is in reference to Nixtrox? I know I need to go back and read somemore! Thanks so much

Maybe this video will help you out.

Here are some more for your viewing pleasure.