Will Air Integration in dive computers replace the SPG?

[stuartv]

It's nice, can't deny that. But what if I happen to dive with backmount gas, 2 or 3 stages? I would need 3 to 4 AI transmitters.

No, you do not NEED 3 to 4 AI transmitters. You can use your AI transmitter on your back gas (or any bottle you want) and still use SPGs on the rest.

As I near completion of AN/DP, I can easily see myself using the AI I already have on my back gas and using only a 1" button SPG on my deco bottle. My back gas is the only thing I'm really going to monitor. Deco gas is something to check to make sure it's full before I start and again when I switch to it and that's about it.

An added utility would be that you would be identifying the tanks with correct gas mixture on the surface, reducing the likelihood of breathing the wrong gas.

I don't quite follow you here.

But, if I recall correctly, I read the manual of 1 multi-gas AI computer before I bought mine. I won't bother speculating on which one it was as I'd probably get it wrong. But, IIRC, there is at least one computer where, if you switch to the wrong gas (say, you switch to your 100% O2 bottle, but you switch the computer to your 50% bottle), the computer AI will detect that the pressure is not dropping on the bottle you selected and alert you that you are not breathing the cylinder you told the computer you are.

Now, that said, if you wanted to take advantage of this additional safety net by using AI on all your cylinders, you are introducing a little extra complexity into your setup. The computer only knows what transmitter it's talking to. It doesn't know what the actual gas blend is that's going into that transmitter (and I don't see THAT happening ANY time soon). So, it would be much easier to screw up by putting the wrong transmitter on the wrong bottle - or, another way of looking at it - setting the wrong transmitter on your computer to the wrong FO2/FHe. You could mitigate this to a large degree with careful labeling of transmitters and by having dedicated reg sets for each gas with a dedicated transmitter on each one, but it still seems like additional complexity compared to having hosed SPGs attached to each stage bottle. And if you don't buy all those many transmitters, so you move transmitters from reg set to reg set, depending on the dive, you amplify your chances of getting your setup wrong.

 

[Diving Dubai]

Stuart.

I appreciate what you're saying. But you're making it too complex. There is nothing difficult about checking you have the correct TX on a particular mix - I do it all the time. You set the mix and with that set connected make sure its reading one TX at a time. I do happen to colour code mine so that the same TX goes on the same reg set and generally but not always on the same tank.

Now I will agree that there is room for error BUT given that people enter the water with their tank valves off - you cant fix stupid. Whatever equipment you use needs some degree of attention - where it be a basic OW1 kit or an advanced complicated tech kit

 

[agilis]

And another thought....

Another topic that comes up is the simplicity of the mechanical over the "complexity of the electronic" which Aglis demonstrates above.

People like mechanical it's simple you can see it working but does that mean it's better?

Years ago I worked on aircraft engines at the switch over between mechanical and flyby wire.

Setting up a mechanical control was almost an art form requiring 2 men 8 hrs with rigging pins to hold the rods i the right place, spring balances, vernier adjustments on the linkages etc just to get it right. 50 hrs later you needed to check everything again after it had bedded in.

Move to flyby wire. No more mechanical linkages. just stepper motors, wires and a computer. you could set the engine up more accurately in 2 hours on the computer. And because it knew its calibration setting it could adjust as settings moved over time.
When a mechanical control failed it was bad - very bad. A fly by wire was designed to fail in a safe way.

I presume a AI computer tests itself in the background where as an SPG doesn't I wonder how many SPG's are calibrated and have a fluid range of movement.

Sometimes there is understandable suspicion if you can't see the way it works as you can a mechanical device. Because you can't see electronic devices work (without test equipment) that doesn't mean electronics are less reliable.

Which you wish to use is of course again personal choice. In the future I can see mechanical SPG's being the high price alternative. Some will pay for a high quality hand assembled item ratther than an electronic device easily made by machine at a lower cost..

I doubt that SPGs will be a high priced alternative, not until they begin appearing on Antique Roadshow and require an explanation of exactly what they are. There are an enormous number of them around, and they are rugged and easy to rebuild. I still have my first SPG, circa 1970, a blackface Scubapro.

Actually I have two of them. Both work extremely well, but have badly scratched faces which obscure the dial. They go back to an era when we still let them drag below us. I now use a smaller version from the same company, but I have Dacors, Oceanics, and others, often made by the same European factories, that I've picked up garage sales for a couple of bucks just so I could play with them. The same with old regulators.

Like old style cars, they are easy to restore. When aircraft mechanics were mentioned it was in the context of flight controls. My remarks about points, rotors, etc.referred to automobile engines, which have become nearly impervious to most backyard mechanics. I understand the utility of simply removing a module and replacing it when the diagnostic computer identifies it as defective, but it's not the same.

There is an aesthetic, even a tactile element involved in all these things.

I financed part of my graduate school experiences by fixing other student's Volkswagens. I still have a collection of VW parts, and recently helped a former student of mine, now in his late 30s, restore a 1966 beetle, 6 volt system and all. I had many of the parts, including the graphite rods for the generator. I had to explain such arcana as the VW heating system and gearbox linkage, and how, when I was a grad student and at least a quarter of the student body drove VWs, we were able to consummate relationships in those wonderful machines.

Looking at the faces of some of those dive computers is for me like looking at something at something written in Tibetan. I realize that it's me, that I refuse to carry around a phone or to own a 'smart phone', that I protect my solitude, my ability to be totally unreachable with the fanaticism characteristic of most survivors of dead civilizations. I mourn the absence of telephone booths, of crowds of people on the street with not a single head bent over some kind of screen, of those yellow boxes of Kodachrome.

 

[stuartv]

I doubt that SPGs will be a high priced alternative, not until they begin appearing on Antique Roadshow and require an explanation of exactly what they are. There are an enormous number of them around, and they are rugged and easy to rebuild. I still have my first SPG, circa 1970, a blackface Scubapro.

Isn't that the point? The suggestion is that the price of a brand new one will go up. And, in my opinion, the near-$100 that you pay for one now, with the required hose, is already high.

Demand for new ones will drop because people are switching to AI and because the market has more and more nice used ones available. When demand (for new ones) drops enough, it will only make sense that the price will go up. The manufacturer has to amortize their overhead over the number of units they are selling.

 

[agilis]

Bah humbug! Dive a square profile and you don't need a computer at all. A watch, an SPG , a depth gauge, dive tables, and a refusal to acknowledge the 21st century is all that's required.

Actually, I consider myself quite progressive and close to the cutting edge technologically ever since I stopped using j valves and began using a submersible pressure gauge. Battery powered UW lights are another advance I've adopted. Those flares were impractical.

 

[undrwater]

Like old style cars, they are easy to restore. When aircraft mechanics were mentioned it was in the context of flight controls. My remarks about points, rotors, etc.referred to automobile engines, which have become nearly impervious to most backyard mechanics. I understand the utility of simply removing a module and replacing it when the diagnostic computer identifies it as defective, but it's not the same.

There is an aesthetic, even a tactile element involved in all these things.

I financed part of my graduate school experiences by fixing other student's Volkswagens. I still have a collection of VW parts, and recently helped a former student of mine, now in his late 30s, restore a 1966 beetle, 6 volt system and all. I had many of the parts, including the graphite rods for the generator. I had to explain such arcana as the VW heating system and gearbox linkage, and how, when I was a grad student and at least a quarter of the student body drove VWs, we were able to consummate relationships in those wonderful machines.

Looking at the faces of some of those dive computers is for me like looking at something at something written in Tibetan. I realize that it's me, that I refuse to carry around a phone or to own a 'smart phone', that I protect my solitude, my ability to be totally unreachable with the fanaticism characteristic of most survivors of dead civilizations. I mourn the absence of telephone booths, of crowds of people on the street with not a single head bent over some kind of screen, of those yellow boxes of Kodachrome.

Thank you. I loved this post.

 

[PfcAJ]

I'm not interested in AI for a number of reasons, but one of those is the lack of availability of replacement parts. The last thing I want is to show up at a dive, my transmitter breaks, and now what?

Ain't nobody got time for that. I can ALWAYS find a spg no matter where I'm at.

 

[stuartv]

I'm not interested in AI for a number of reasons, but one of those is the lack of availability of replacement parts. The last thing I want is to show up at a dive, my transmitter breaks, and now what?

Ain't nobody got time for that. I can ALWAYS find a spg no matter where I'm at.

If the dive is at all important to me, I'm taking an SPG in my reg bag that I can just swap the transmitter out for at any time. Lack of replacement parts would be one of my LAST reasons for choosing not to use AI.

ps. if you can ALWAYS find an SPG, then you can always replace your AI if it breaks, right? Maybe you just have to carry a HP hose and spool with you?

 

[dmoore19]

I had that happen to me once. One of the guys on the boat had problems with his SPG. I had one in my bag that I loaned him. My AI worked flawlessly.

I'm not interested in AI for a number of reasons, but one of those is the lack of availability of replacement parts. The last thing I want is to show up at a dive, my transmitter breaks, and now what?

Ain't nobody got time for that. I can ALWAYS find a spg no matter where I'm at.

 

[PfcAJ]

If the dive is at all important to me, I'm taking an SPG in my reg bag that I can just swap the transmitter out for at any time. Lack of replacement parts would be one of my LAST reasons for choosing not to use AI.

ps. if you can ALWAYS find an SPG, then you can always replace your AI if it breaks, right? Maybe you just have to carry a HP hose and spool with you?

Then you've got a training scar from not routinely managing a pressure gauge.

And no, a mom and pop dive shop in SE Asia is unlikely to have spare AI stuff that's compatable with your computer. Even less likely is for there to be one on the boat.