tank ?

[RDRINK25]

I set my computer for a 80 cft tank when it was a 100 cft. So if it was reading 500 psi what was it really?

 

[Doc]

It was 500 psi.

really

 

[Linedog]

A 130 at 500 psi will read 500 psi.

really

 

[RDRINK25]

Then why does it ask for the volume? Sorry to ask a stupid question I am just confused.

 

[Insta-Gator]

Volume is pressure x cylinder constant. Faber 117 is 3442 x .03399. Each cylinder has it's own constant. PSI is just PSI.

 

[RDRINK25]

Ok got it. I got mixed up when I downloaded my logbook and it said I was using an al80 when I was really using a HP100. 500 psi is 500 psi and only thing ws wrong was the volume?

 

[hypertech]

Right. It might be doing a SAC rate calculation for you. It would need the volume to do that. It might also just be noting it for your log.

 

[tbone1004]

yeah, SAC rate is usually calculated but on the AI computers most of them will calculate dive time remaining based on your SAC rate. It'll give you the NDL and then the time left based on your SAC next to each other or something depending on the computer. If you're converting SAC, then you'll have to find the tank conversion factors for each of the tanks and do some math.

 

[davetowz]

Not knowing what computer you are running I would guess that it wants that info to calculate" time remaining for this dive" What computer are you using?
I have not heard of any A/I computer that will base a pressure reading off of the volume, only the pressure it senses. Does the manual indicate anything about why they want you to set volume?

 

[hypertech]

You don't need volume to calculate time remaining for this dive. Its a constant that cancels out. You don't need to know the specific SAC rate. Just the rate at which the pressure is decreasing, the current ambient pressure (depth) and the pressure remaining.