Computers in Air Pockets

[voidware]

Of the air pockets I have encoutered in my extremely limited overhead experience, they have been inches deep of exhaust. But I was wondering if I brought my computer into a cave or a real wreck and ventured into an air pocket would it still take into account my nitrogen loading or would it stop? I have a suunto vyper if that matters. thanks,
brandon

 

[Rick Murchison]

It'll keep right on workin'...
In fact, if you slip up and activate your computer while you're in an airliner, when you descend to land it'll start a dive to about 7' and stay there until you either get back on the plane or take out the battery.
Rick

 

[Ontario Diver]

The Nitrogen loading will be correct. If you are in an air pocket it will be at the same pressure as the water and that is half of the equation (the other half is time )

Although I couldn't find anything in my vyper manual

 

[dc4bs]

Not sure, but most computers have a 10 minute or so surface interval required before a dive is "closed". If you go back under before the 10 minutes are up, it calculates the second dive as a continuation of the first dive.

I believe this goes back to the navy dive tables that requre a minimum surface interval of 10 minutes between dives.

For the 10 minute clock to start normaly requires that the pressure on the computer go down to about 1 atmosphere (surface) so there should be no problem at depth.

My new computers manual says to always pressure test the unit under water (not just air pressure) as air at high pressure may cause problems with the pressure sensor designed for water only use.

I don't know if this would apply to a visit to a high pressure airpocket at depth. I'm not sure I'd want to risk it though (kind of expensive computer).

 

[dc4bs]

Originally posted by Rick Murchison
It'll keep right on workin'...
In fact, if you slip up and activate your computer while you're in an airliner, when you descend to land it'll start a dive to about 7' and stay there until you either get back on the plane or take out the battery.
Rick

Well, if you start it just before descent maybe.

My older computer will turn off after 10 minutes of inactivity.

I get a kick out of my new computer though. It keeps track of pressure once a minute or so even when it's "off".

When you fly somewhere with it or drive over mountains you can look at the record of the trip after you download to your PC. It lists pressure changes in 500 foot increments and what time it recorded them. The maker says to keep it in your carry on bag as it actualy credits you a tiny bit for offgassing that occurs during the flight to the dive trip... If you put it in the unpressurized hold it may credit too much or get confused for a few hours after the flight untill it assumes you are nitrogen saturated at sealevel again.

Kinda cool but also necessary to know in order to use it properly.

 

[Rick Murchison]

Originally posted by dc4bs


Well, if you start it just before descent maybe.

Subject is activating your computer in an airliner and screwing it up by having it start a dive on descent.
You are correct. The activation has to be within the time limits of the computer for a descent - most have a two hour limit.
Rick