Will Air Integration in dive computers replace the SPG?

[tbone1004]

Yes, but given that transmitters use very little power, the battery could potentially be fully charged every time you pressurize the first stage. This means you may be able to significantly reduce battery replacement which would be a big step in making AI replace the SPG. Not only do you eliminate the hassle, but you eliminate the potential for flooding because the diver did not re-seal the case properly or damaged the o ring after the battery replacement.

---------- Post added January 12th, 2016 at 08:49 PM ----------

I'll add that you should read the Georgia Tech article I linked. It's not motion that creates the electrical charge, it's pressure. The pressure deforms the material which releases electricity and then is stored in the battery. The process can be repeated and continue to deliver a renewable energy source.

pressure causes deformation, deformation is motion. Transmitters use a whole lot more power than can be generated on a single deformation which requires cycling of the piezo button. Not practical and the transmitters require low power, but fairly high voltage for effective broadcast of the signal, this can't be generated with piezo buttons without cycling and a fairly high rate, and since that would require air, would have to be incorporated into the first stage itself to take advantage of the diaphragm cycling, but even that isn't fast enough for it to be reliable, and only works while you're breathing on it. Think about it this way, if it actually generated enough energy to power anything meaningful, they would have put them under every heavy thing in the world to create perpetual energy....

Regarding CCR's, they won't take over OC, ever. The technology is simple, gas flows through sorb, CO2 gets removed, O2 gets added to replace it. BUT, they require very particular adjustment to the individual, are horrifically expensive, require custom machine work, and even if they were $2k instead of $10k, they don't provide anything significant over open circuit for 99% of the recreational diving.

The biggest problem with AI becoming universal, because that is the title of the thread, AI replacing SPG's, is what was mentioned a few posts above this. How do you make sure the pressure in the tank you want is the one you are looking at when you carry multiple bottles? How will the computer keep a bottle in the same position on a screen when you drop it off and pick it back up? That's one of the biggest issues right now and while I would be 100% OK with button gauges on one side for a quick sanity check during tech diving, and can't wait for a good computer mfg to come out with inexpensive wireless transmitters, the ROI for the manufacturers just isn't there at this point.

 

[halocline]

Where's the sense in checking less often? Do you want OOA to be a surprise? Don't you watch your depth gauge and timer? Wouldn't it be convenient if you knew your remaining gas concurrently at knowing your depth and run time?

Experienced divers can usually predict their air consumption fairly well and are not at all surprised towards the end of a dive. In recreational settings, I check my pressure before beginning the dive, again about 10 minutes in to confirm my general rate of consumption, then maybe again at about 30 mins, or some appropriate time given the dive profile, and again towards the end of the dive. Unless there's an obvious problem like a major leak or unexpected air donation/sharing, I'm going to know pretty well where my pressure is during any specific point in the dive. It's predictable.

Depth, OTOH, is something every diver wants to know all the time, and that's not always predictable, and you want to know it precisely. Dive plans depend on it. Same thing with dive time, although that's also linear and therefore reasonably predictable, but you do want to have a fairly precise idea for dive planning.

It's not that monitoring gas pressure isn't important, its just that it's easy to do with an acceptable amount of accuracy in recreational diving without constantly looking at the pressure gauge.

More technical dives with more complex (and rigid) gas planning scenarios require more precise pressure monitoring, but again, usually divers doing this sort of dive have a strong ability to even more accurately predict their pressure at any given point.

 

[casts_by_fly]

Yeah, but the actual thing that keeps you from crashing - pumping brake pressure lines or turning the steering mechanism - isn't fly by wire like on a commercial jet. It's still analog, and I don't think that's because we don't know how to put fly by wire in a car...

[-]My turning mechanism is electronic fly by wire (BMW). I think almost all BMWs are electronic servo based steering now. Transmissions are the same, but I will give you brakes for now.
[/-]

Sorry Mike, Scratch that. When you were saying drive by wire, I thought you were only talking about the hydraulics being replaced by electronics, not wireless connections. The BMW uses an electronic wired system from the steering wheel to the rack and pinion. The rack and pinion are electronically controlled with motors, no hydraulics.

thanks
rick

 

[CuzzA]

Yes, I don't disagree. The question was more about having the conversation of the evolution of technology in diving gear. Being that nearly every computer manufacturer now offers AI can we expect that it will replace the SPG. Not about how often someone checks their gas or that experienced divers typically know what their tank pressure is.

Lets assume the aforementioned requirements of AI have been met (Equal Reliability, Equal Durability, Size, Cost and Universal Standardization) What other reasons would a typical RECREATIONAL diver choose not to use AI instead of an SPG?

 

[Wookie]

Yes, I don't disagree. The question was more about having the conversation of the evolution of technology in diving gear. Being that nearly every computer manufacturer now offers AI can we expect that it will replace the SPG. Not about how often someone checks their gas or that experienced divers typically know what their tank pressure is.

Lets assume the aforementioned requirements of AI have been met (Equal Reliability, Equal Durability, Size, Cost and Universal Standardization) What other reasons would a typical RECREATIONAL diver choose not to use AI instead of an SPG?

None, but we've now entered the realm of "what if?", which is a fun game to play, but isn't terribly practical.

What if Io had a liquid sea at 25 degrees C and there was regular passenger service? Would you dive there?

 

[casts_by_fly]

If you consider that the majority of divers (not the majority on SB) are garden variety open water rec divers, then air integration will replace SPGs when the cost is such that it is equivalent or nearly so and the reliability is good enough for a vacation dive. The first manufacturer who can sell a computer + transmitter for the same price as a computer + SPG will open the floodgates and others will follow. The proceeding economy of scale will mean more investment into the technology, better user experiences, and higher acceptance. There are some divers who won't switch, but the majority will. If I could replace my SPG with air integration for no added cost I'd do it in a heartbeat. It is 1 less thing to wrap up in my reg bag for traveling, 1 less hose to clip onto my BCD in the water. For no extra cost? No questions asked.

thanks
rick

 

[tbone1004]

the fact is you will never get equal reliability with digital sensors over an analog bourdon tube, just isn't going to happen, sorry. Better accuracy, potentially only because of the small size, but never better reliability. There is a reason almost all high pressure systems that need pinpoint accuracy still use big ass analog gauges. The reliability is good enough now that to me it doesn't matter. If the transmitter fails, the dive is over, but for tech dives I would put button gauges on just in case *obviously good for sidemount only*
Equal durability, not going to happen. Good SPG's are a block of machined brass with a big hunk of glass on the front, you can run them over with vehicles and they don't care. Hell I saw a couple a few weeks ago in cave country that had been slung out of the bed of a pickup truck at highway speeds and landed on the asphalt with a couple new scratches on them but still worked fine. Durability for me comes with size, once they are small enough to tuck under the first stage and tank crown, that will help greatly with durability.

Size/Cost are the big ones right now. If they were about 25% smaller, and cost about $100-$150 and the computers were no more expensive, then I would switch today. I.e. Seabear T1 for around $700-$800, and transmitters at the cost above, I would switch at least my primary regulators over.

Universal standardization will never happen as long as Suunto is in the business, unless everyone standardizes to what they are using, which probably won't happen due to crazy licensing costs.

 

[doctormike]

What if Io had a liquid sea at 25 degrees C and there was regular passenger service? Would you dive there?

Only on the Spree. Figure out the fuel costs to get her there, and we'll see what we can do as far as booking a charter.

 

[chrisch]

....
Lets assume the aforementioned requirements of AI have been met (Equal Reliability, Equal Durability, Size, Cost and Universal Standardization) What other reasons would a typical RECREATIONAL diver choose not to use AI instead of an SPG?

I think - if you satisfy all those requirements - you can maybe expect 80% or more recreational divers to go that route. It will still take a while though as most divers will only move to AI as they replace existing gear. If you say the typical computer has a 15 year life then you need to add 15 years or so beyond the point you created to get to that kind of penetration figure.

You are still going to get residual pockets of mechanical SPG - for example rental kit. (And all us old duffers that just want to stick in the mud )

 

[Lorenzoid]

Yes, I don't disagree. The question was more about having the conversation of the evolution of technology in diving gear. Being that nearly every computer manufacturer now offers AI can we expect that it will replace the SPG. Not about how often someone checks their gas or that experienced divers typically know what their tank pressure is.
. . .

I don't see how the second part--how often a diver needs to check his gas--is not linked to the first part. If I don't need to check my gas more than a few times during a dive, at almost zero inconvenience to me, then at least for me, the inconveniences of dealing with a transmitter stuck to my first stage outweigh any benefit of the system. Assuming equal reliability/durability, etc., I just don't see any benefit. Others have mentioned things that they see as benefits that apparently outweigh such inconveniences, such as gas usage logging, but that is not of value to me.

Maybe in addition to "Equal Reliability, Equal Durability, Size, Cost and Universal Standardization" you would need to add "transmitter that requires no attention from the user--as though it were invisible."