Bar and PSI

[lottie]

I had a friend come over for a couple of weeks from the UK (she flies back tomorrow) and we managed to get in a good few dives as well.

her SPG is in metric, so its in bar, whereas mine is imperial and in PSI.
One of the DMs said that 700psi was 100 bar and another said it was 50 bar..so which is it?

[The Publisher]

700 psi is 48.275 bars.

http://www.worldwidemetric.com/metcal.htm

[lottie]

Thanks - and the link...I've bookmarked that for future reference

[frozenwarp]

Being an Aussie i also use Bar and due to the training company (SSI) being american based, in my case first list everything in imperial then in metric and it has the conversion of 14.7PSI = 1 bar
therefore 700psi = 47.62 (i know wow what a difference too the above post lol)
that being said i'd be more inclined to follow the link above conversion

anyway thought id throw that out there

[hbh2oguard]

In college text books it's 14.7 so I think you're right.

[hbh2oguard]

Looking around the net and 14.5 seems pretty popular. Given that tanks are at a relatively low pressure the .2 difference doesn't make a huge difference. Say the normal every day average fill in the states is 3000psi using 14.5 that converts to 206.9 bar and using 14.7 that's 204.1 bar. That comes out to a difference of 2.8 bar or about 40psi. Unless you have a digital spg I don't think you'll notice a difference. When you factor other conditions like elevation,temp., etc you won't notice the difference.

[hbh2oguard]

Ok I'm 99% sure I know the difference. One is at STP(standard temp. & pressure) and the other isn't. Again you're never going to be diving a stp, plus it would be very very cold, so it doesn't really matter. All you have to worry about is that your spg doesn't say 0

[The Publisher]

Ok, just for fun, I used a bunch of other online metric conversions, and for 700 psi, here is what I got in bars:


48.2630
48.2633
47.6
48.263298999999

Not particularly consistent!

[hbh2oguard]

3 out of the 4 are pretty close. But I had the same exact problem. I'll try to remember to ask one of my professor what they use.