Air Integrated Computer - Question

[nv]

All,

Do air integrated computers make calculations based on your consumption or do they just display cylinder pressure? Better said: is your consumption factored into the calculations your computer displays?

Thanks!

 

[AfterDark]

Some do some don't. Don't know which ones do or don't.

 

[Scared Silly]

Many computers will calculate a remaining air time before it gets to the reserve pressure. I.e. the air time at zero will be the reserve pressure. At least with Suunto I have never found the calculation to be that accurate.

 

[eelnoraa]

My computer, Oceanic VT3, will calculate remaining dive time based on air remaining and NDL remaining. The shorter of the two will be remaining dive time. The air remaining time calulcation will take into account my consumption rate. So at remaining dive time = 0, I can ascent at 30ft/s, do 3 minutes at 15ft safety stop, then surface. And I should still have a min reserved air (another preset parameter in the computer) in my tank.

It looks pretty smart at first, but I soon realized there is corner case. The air remaining time is calculated based on my own consumption, so when remaing time = 0, there is only enough air to me to surface. If thing happens and I need to share air with my buddy, we will NOT have enough air for a proper ascent. So I ditch the AI altogether now and do gas planning myself now.

 

[NAM001]

I agree with eelnoraa. My aires t3 elite is more or less teh same computer. I can just set my end dive presure to say 1000 and all is well. i have never done that but i could. I have varied the end psi from 600 to 300 depending on the tanks config used and the dive. but normally I am out of the water long before that psi is hit. I would not be concerned about the problems with the integrated aspect of the computer other than the vulnerability of the sender to being damaged or oing out of calibration. I do have a spg in addition to the computer. Just having the psi data logged in the computer is usefull when you replay the dive for critique.

 

[nv]

Thank you for your responses. I should have been a little more specific; I was referring to your consumption rate and nitrogen loading. For example, your NDL is 120minutes and your burn through your air supply (80 alum cylinder in 20 minutes) vs I dive the exact same profile, but burn only 800psi (topside with 2200). Will these computers calculate the nitrogen loading based on consumption?

 

[Atom]

Nitrogen loading is not based on air consumption, it's driven by the partial pressure difference in Nitrogen between the gas in your lungs and what's in your blood. So doesn't matter how much you consume.

But Suunto computer will display the "air time" remaining. How much time do you have at current consumption/depth before your reach the user configurable reserve pressure.

 

[nv]

Nitrogen loading is not based on air consumption, it's driven by the partial pressure difference in Nitrogen between the gas in your lungs and what's in your blood. So doesn't matter how much you consume.

But Suunto computer will display the "air time" remaining. How much time do you have at current consumption/depth before your reach the user configurable reserve pressure.

Thanks for clarifying that for me. I was viewing it differently. Well for that dive profile I am down just about 75minutes. At the spielgel grove, same day and cylinder size, my BT was 31 minutes and still had 1100 psi at the surface - came up early because dive buddy was on reserve.

 

[DevonDiver]

The last AI computer I used was a Suunto 'Eon'. I'm pretty sure it'd be classed as 'vintage' diving equipment now. That provided an 'air time remaining' reading, based on consumption rate.

 

[Stealth Mode]

I use a Sherwood Wisdom and it is VERY accurate.It calculates consumption rate and I have mine set for a 500 psi reserve after safety or deco.I still do manual calculations before dives.As for buddys air I can just hand off my pony.