EDIT...
After tinkering with figures, ignore my dribble below... check this out
Add both tanks
2800
3300
6100
round UP to the next divisible by 3's (we are working backwards here)
6300
divide by three
2100
There, you turn when both tanks are down to 2100
Easy math
ignore everything below this:
OK,
In the real world I'm going to start off with two separate pressures, then the first thing I'm going to do is start on the higher pressure tank and breath it down so they are equal. Now at the turn I want them to both be equal,
I'm pretty sure this gives an accurate thirds...
Add Tank A and B, divide by three, and you have the turn around pressure for each tank.
Example:
If I start my dive with one at 2800 and one at 3300
2800
3300
-----
6100 /3 = 2033.33 (round 2033 UP... always up) to get 2100
in other words, you would dive until they each reach (an absolute minimum of) 2100 and turn.
Unless Im mistaken, this gives accurate thirds and you eliminate the need to figure out a third, divide by half, subtract from both tanks etc etc etc... and both tanks will be equal at the turn point
Can some left brained mathematician check and see if I'm right?
I have no problem with this thread getting hijacked. In fact, I rather enjoy learning how you guys calculate the turn around point.
Also, I wrote up an equation for calculating turn around point based on the teaching from the power points.
Tank A: X (Always the tank with lower pressure)
Tank B: Y (Always the tank with higher pressure)
Tank A Turn Around Time (TAT): (X/3) x 2
Balancing pressure between Tank A and Tank B: Y - X
Tank A TAT - Balancing pressure between Tank A and Tank B: Z
Z/2 = W
X - W = Turn Around Pressure
I am going to have this equation printed out, laminated and glued to my wrist slate.
