thewkb wrote:Convert feet to atmospheres and BAR and vice versa?
Great! A simple question. I can answer simple questions.
Here is the way to do it:
The first formula I made years ago to use was for Pressure at ?? Depth and is:
14.7*Depth/33+14.7=Pressure
What you want is to be able to put in a depth figure and know how many atmospheres it is, which can be done this way on an ordinary calculator:
Depth/33+1=Atmospheres = 33 feet down would be 33 / 33 which = 1 atmosphere + the 1 we walk around in = 2 atmospheres. 66 feet down / 33 = 2 + the sea level atmosphere you add of 1 would be 3 atmospheres total at 66 ft down. If they were SCUBA diving and went down 103 feet, then they were at 4.121212121212 atmospheres at 103 feet deep. Numbers are cool to work with and formulas are really cool.
I just looked at it today and thought, hummm, if we change this around and it works great for finding how many atmospheres at depth you are. Really really simple. For every 33 feet you go down, is 1 atmosphere. Just take the Depth, divide by 33 and add 1 more for the pressure at sea level. Pretty cool.
1 atmosphere is now defined to be 1.01325 bar exactly. So, at 10 atmospheres (which is 297 feet down, remember, it can't just be 10 x 33 because we are walking around in ONE atmosphere, so it would be 9 x 33 to get the correct distance you would be down) you would be off by 1.94775 pounds, instead of 147 lbs it would be 148.94775 lbs. That will give you something to work with.