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MxDiver
08-06-2007, 10:51
How does AI come into play when you are using more than one tank? No, Iím not referring to doubles; I am talking about having separate tanks, as in two mixes. The VT-3 for example has the capability to track up to three mixes (or tanks). How does the computer work this out? Will it take into account all the volume Iím carrying? Or, are AI calculations limited to the one cylinder at the time?
What if you are diving doubles and carrying a spare 40 ft? If the computer calculates air consumption based on PSI drop the air consumption rates shown will be drastically different, I did not find any way to correct for these volume differences on the owners manual, maybe it can be done through the software?

medic001918
08-06-2007, 11:01
I don't believe an AI computer can monitor different tanks and their pressures unless you had a transmitter on each tank. As far as handling different mixes, some computers are capable of switching mixes in the middle of a dive. If you're getting into the kind of diving that you're using multiple gasses and different tanks, you can probably handle figuring things out without your computer.

Shane

ScubaToys Larry
08-06-2007, 11:10
Yes, with 3 transmitters, 3 different tanks, and even 3 mixes, you punch in the mixes of the tanks you are carrying. When you switch to a different tank, you push the button to switch the computer, and it re-calculates on the new consumption based on the drop in that tank for your time and it recalculates NDL based on the new mix. Pretty neat eh? So it will tell you time left of that tank, but it will not add up all your tanks together for you. Make sense??

So it doesn't really care about the volume. It's looking at how many PSI drop are you getting per minute, then extrapolating that based on the remaining PSI in the tank. Doesn't matter if it's a 6 ft pony or a steel 130.

ianr33
08-06-2007, 11:22
Yes, with 3 transmitters, 3 different tanks, and even 3 mixes, you punch in the mixes of the tanks you are carrying. When you switch to a different tank, you push the button to switch the computer, and it re-calculates on the new consumption based on the drop in that tank for your time and it recalculates NDL based on the new mix. Pretty neat eh? So it will tell you time left of that tank, but it will not add up all your tanks together for you. Make sense??

So it doesn't really care about the volume. It's looking at how many PSI drop are you getting per minute, then extrapolating that based on the remaining PSI in the tank. Doesn't matter if it's a 6 ft pony or a steel 130.

Why would anybody bother with 3 tanks on an NDL dive?

MxDiver
08-06-2007, 11:47
So basically the computer will be freaking out when you are either down to your last few hundred psi or NDL for the mix until the switch is made.
What if you go into Deco mode? I assume the computer will adjust deco times based on the new mix?
Don’t get me wrong; I am not trying to find a computer that will take the place of tables and my brain in a Tech dive, or any dive for that matter. But I am curious as to what are these computers really capable of.

ScubaToys Larry
08-06-2007, 11:51
Yes, if you are past your NDL at any point, it will tell you how much deco you will have to do and at what depth based on the gas you are on at that time.

CompuDude
08-06-2007, 12:30
So basically the computer will be freaking out when you are either down to your last few hundred psi or NDL for the mix until the switch is made.
What if you go into Deco mode? I assume the computer will adjust deco times based on the new mix?
Donít get me wrong; I am not trying to find a computer that will take the place of tables and my brain in a Tech dive, or any dive for that matter. But I am curious as to what are these computers really capable of.

Exactly. They freak out at you until you switch tanks, then it recalculates and calms down (assuming you now have enough gas to do your stops, etc.).

This is one reason, incidentally, that you don't really use recreational dive computers, even with this capability, in computer mode for technical dives. You put them into gauge mode. You can then still use the computer, and switch tanks to monitor gas supply, etc., but that's really more for dive logging purposes than for monitoring limits and RBT. The computers don't monitor RBT (I think) in gauge mode.

cummings66
08-06-2007, 12:57
By freak out, if you mean it warns you then yes they do that. I've done dives using different mixes, ie 40% and 21%. The computer will tell you about the mod and you can make it happy by switching tanks. It is kind of interesting watching the display recalculate your bottom times and status as it uses the new mix. So if you make the switch to 40% as soon as you can you can see how the effect happens as far as the computer is concerned.

But it does take a transmitter for each tank and also you need to watch how you enter the mixes. If you set 40% for #1, then #2 and #3 will also be that at a minimum. You need to set it backwards to work right, #2 or #3 being the stronger mix with #1 being the weakest.

CompuDude
08-06-2007, 13:17
By freak out, if you mean it warns you then yes they do that. I've done dives using different mixes, ie 40% and 21%. The computer will tell you about the mod and you can make it happy by switching tanks. It is kind of interesting watching the display recalculate your bottom times and status as it uses the new mix. So if you make the switch to 40% as soon as you can you can see how the effect happens as far as the computer is concerned.

But it does take a transmitter for each tank and also you need to watch how you enter the mixes. If you set 40% for #1, then #2 and #3 will also be that at a minimum. You need to set it backwards to work right, #2 or #3 being the stronger mix with #1 being the weakest.
When my computer starts beeping like crazy and icons on the screen start flashing, I consider that freaking out. ;)

You're right about needing a transmitter for each tank, of course.

The setting process, however, varies for each computer. My Uwatec does not require the methodology you speak of in terms of how to enter the mix data per tank.

ScubaToys Larry
08-06-2007, 13:21
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When my computer starts beeping like crazy and icons on the screen start flashing, I consider that freaking out. ;)

You're right about needing a transmitter for each tank, of course.

The setting process, however, varies for each computer. My Uwatec does not require the methodology you speak of in terms of how to enter the mix data per tank.

On my last dive, mine just started flashing the emergency for DAN. Is that a bad sign?

BSea
08-06-2007, 13:25
For those thinking of a multigas computer, be aware that the suunto vytec does not use multiple transmitters. It can look at 1, but for the other gasses, it just does the calcs based on time & depth & mix. It wasn't a big deal to me since I wasn't going to spring for the extra transmitters anyway.

CompuDude
08-06-2007, 13:27
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When my computer starts beeping like crazy and icons on the screen start flashing, I consider that freaking out. ;)

You're right about needing a transmitter for each tank, of course.

The setting process, however, varies for each computer. My Uwatec does not require the methodology you speak of in terms of how to enter the mix data per tank.

On my last dive, mine just started flashing the emergency for DAN. Is that a bad sign?
Yes. LOL

I took my computer along for a chamber ride the other day (part of my divemaster course, not an actual emergency). We rode Navy tables down to 165', played some games, and back up. Needless to say, my computer was pretty furious with me... Navy tables are a lot more liberal than most computers, on square profiles like that.

It's bad when the screen says "SOS". :smilie39:

It was 24 hours before it went back to normal! (Not that I was going be diving for 24 hours after that anyway)