converting PSI

[deepocean]

Hi

i am reading the first GUE tech(1) book. I have a few questions.

What does ATA means (to messure pressure ) What does ATA stand for?

And i am going on holidays. I think there they are not using the bar system when counting the amount of air left in tanks. I think they will use PSI's for measuring pressure.
Anyone any tips on converting PSI's to Bar's and vice versa?
I hate this, why everyone cant just use one system? PSI or bar does nt matter to.

Which one is better in your opionion? Maybe one is more easier/more accurate........? Tell me :D

And if i say the maximum depth is 100fsw where does this fsw stand for? Feet s.....w....?

greetings, Xerxes

[owlbill]

ATA = atmoshperes absolute (water pressure plus air pressure)

PSI - BAR = multiply BAR by 14.5 to get PSI

FSW = feet sea water

Hope this helps. I did keep it short.

[Zept]

To convert bar to psi and vice versa, in your head, while diving:

-- Take a number in bar, multiply by 10, then add half as much again. For example, 200bar times 10 is 2,000. Adding half as much again gives you 3000psi.

-- Take a number in psi, divide by 10, then divide by three, then double it. For example, 750psi divided by 10 is 75. Dividing that by three gives 25, and doubling that gives 50bar.


Z

PS: People who measure pressure in psi usually breathe their tanks down to 500psi, whereas people who use bar stop at 50bar... which is 750psi.

[Charlie99]

In most cases, the diver just wants a general feel for the equivalence. I find 70 bar per 1000psi is easy. For AL80, the following is easy:

full = 3000psi = 210 bar
2000 = 140
half = 1500 = 100 bar
1000 = 70
500 = 35


Even this was too complicated for a metric dive buddy I had on a Fl Keys boat, so we settled on the simpler version:

SPG in the yellow: we should be headed back to the boat
SPG in the red: we should be at safety stop or on the boat.

p.s. An AL80 is roughly an 11 liter tank.

[Charlie99]

Feet to meters: divide by 10, multiply by 3, .
. example for 80': 80'/10=8 8x3=24 meters.

meters to feet: divide by 3, add a zero.
. example: 30 meters/3 = 10. add a zero to get 100'.

[deepocean]

Hi

he thnx guys. valuable info. Happy diving all :)

Xerxes