Air vs Nitrox (Revisited)

[Stone]

About a month ago I posted an interactive "Nitrox vs Air Graph" that was viewable only if you had Excel on your computer.

Here is a link to a non-interactive graph that I hope is viewable by anyone interested.

Be sure to look at the assumptions below the graphs!

Air vs Nitrox Graph

You can also get to the graph by clicking on the URL below my name and going to the "Dive Documents" page on my website.

 

[blacknet]

Hello,

Well that most certainly is interesting, however there's many inaccuracies with the graph. Like it does not state what the assumptions are. There's also allot of variables that would change the nature of the graph. However I do not thing that is the point of the graph. What would be most helpful to those that don’t know how to interpret data from the graph is a small 1-2 paragraph summary describing the results.

Ed

 

[Stone]

Blacknet,

The assumptions are just below the graphs.

 

[The Chairman]

I liked the graph just fine. It gives an analog view of what is happening, and that helps anytime. Humans can not decipher numbers (digital) as quickly or as efficiently as we can decipher graphic visual relationships (analog), like analog meters and graphs. I do like the way you terminated the various mixes when they encountered an unsafe depth. An "X" or a "Max Depth" would make it even more obvious.

 

[Stone]

Per Netdoc's suggestion, I have terminated the Nitrox plots at (near) the appropriate Max PPO2 depth.

I also amended my original post to make sure viewers scroll down to the assumptions below the graphs.

Here's the link again:

Air vs Nitrox Graphs

 

[roakey]

Stone,

If you're taking suggestions, let me give you a human factor one.

Put 0,0 at the top left of the graph, with depth going down the left side and time going along the top (in other words turn the graphs clockwise by 90 degrees).

This will make the graph reflect the way we think about both depth (going from top to bottom) and time (going left to right). The graph will be much more intuitive this way.

Roak

 

[Stone]

Roakey,

Thanks for the input.

Put 0,0 at the top left of the graph, with depth going down the left side and time going along the top (in other words turn the graphs clockwise by 90 degrees). This will make the graph reflect the way we think about both depth (going from top to bottom) and time (going left to right). The graph will be much more intuitive this way.

I agree that it seems to make sense to represent depth as up and down, so I turned a print-out of the graph 90 degrees to see what it did for me. My intuition may have been overridden by many years of plotting the independent variable on the x-axis and the dependent variable on the y-axis, but it was actually harder for me to interpret the relationship with depth on the y-axis.

On a more pragmatic note, since the data comes from the tables with NDL as a function of depth (depth as the independent variable), and I don't know how to make Excel put the independent variable on the Y axis, the data would have to be re-mapped so that for a given Max NDL, you get a depth. Without equations for the gas lines, that requires a little more work than I'm willing to take on.

 

[The Chairman]

May I reproduce and use your graph when I start teaching classes (which will be AFTER I finish my IDC and PADI exam)

 

[Stone]

NetDoc,

Please use the graphs (Excel or HTML) any way you see fit. If you download the Excel file, you can move the "tank line" up and down on the graph just by changing a single number.

 

[Bob]

Stone,
Thanks for the comparsion. Good stuff.
:tree:Bob