Will Air Integration in dive computers replace the SPG?

[Centrals]

As long as I can still buy the spg, I see no reason to change to AI.
spg is accurate and reliable enough for the purpose.

 

[tbone1004]

What you guys aren't realizing with the O2 sensors is that they measure PPO2, not FO2. Due to this, they would have to be calibrated against whatever pressure they are reading, which of course changes with depth, tank pressure, etc etc. It is not feasible.

Regarding other types of cells, CCR uses stock parts because they're readily available, but different types of sensors are being developed for other markets and as they come available, I'm sure the industry will adopt them

 

[kafkaland]

What you guys aren't realizing with the O2 sensors is that they measure PPO2, not FO2. Due to this, they would have to be calibrated against whatever pressure they are reading, which of course changes with depth, tank pressure, etc etc. It is not feasible.

Regarding other types of cells, CCR uses stock parts because they're readily available, but different types of sensors are being developed for other markets and as they come available, I'm sure the industry will adopt them

The whole point of an AI sensor is to measure and transmit pressure. If you have that, and PPO2, conversion to FO2 is trivial.

 

[CuzzA]

I just threw CO and O2 analyzing out there, but after further thought and the responses I agree that with today's technology it's not feasible. Too expensive, probably too bulky and unreliable without constant service to the sensors.

But to expand more on decompression's suggestion of pressure being used to power the transmitter I dug a little deeper and found this invention from Georgia Tech. I have heard about it before, but never gave it much thought as they suggested the tech be used in shoes to power cell phones which I see a lot of shortcomings with that idea. However, for an AI transmitter, it seems like a match made in heaven.

Self-Charging Power Cell Converts and Stores Energy in a Single Unit

 

[tbone1004]

not trying to rain on anyones parade....

piezo membranes require motion to work, not constant pressure. Mechanical energy requires motion, no motion going on on the HP side of a regulator.

Regarding the O2 sensors, I don't believe that the sensors will tolerate a PO2 of 250... Could be wrong, but don't believe they'll play nice with that high of a PO2, would be quite a large charge, and would also be damn near impossible to calibrate, on top of not actually being able to work without a HP bleed system installed because you need to purge the gas around the sensor in order to ensure an accurate reading. Very complicated solution in search of a problem that doesn't exist. Divers putting in the wrong nitrox mixes don't really matter as long as they put them in low, i.e. if they're diving 32% and they put in 31% it's not the end of the world they'll just have a bit of extra deco involved if they go into deco

 

[CuzzA]

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.

 

[eelnoraa]

I have had my share of problem with wireless AI. So I converted from AI back to SPG a few years ago. Until AI is really mature, I am a SPG guys. I guess one day

 

[DevonDiver]

AI technology is proven to work. With every new computer and transmitter created, logic tells me the reliability gets better and better. I personally own an AI computer and it has never failed me.

1. Proven to work and proven reliable are different factors.
2. Improving reliability doesn't mean absolute reliability.
3. Personal experience (Dives 25 - 49) is a small sample size. At 8000+ dives, I've learned one thing... everything fails sooner or later. I'd say that AI failure (varied failure types - battery, sync, electronics etc) was relatively high frequency compared to most scuba equipment.

The reason why AI is acceptable (versus failure frequency) for recreational scuba diving is because it is not life support equipment. In the event of failure, the recreational diver can abort their dive and surface safely. Failure is (should be!) a matter of inconvenience and lost dives.

 

[dumpsterDiver]

One issue I have had with the transmitters is that they make GREAT handles when handing up a scuba unit from the water into a small boat...I recently grabbed one and started pulling up, before I realized what I was holding.

I suspect it would not be too hard to rip one off... on accident ..say in the dark, when it is rough etc..

I had good luck with an air integrated computers, but they had hoses and I got them cheap and they worked for quite a while .. until they failed, but when deep on air, and doing deco (without any written plans) and solo and spearfishing, it is kinda nice to see an ascent time and an air time displayed. I never carried redundancy on the dive (other than a Casio G shock) ... on multiday trips, I always just bring a complete spare regulator ..

 

[CuzzA]

Andy, Indeed I don't have a ton of dives under my belt yet, but I can make some observations from other's experiences.

If it were statistically proven or time tested AI is as or more reliable than an SPG and meeting the other requirements we've discussed I think it's quite possible it will replace the SPG, atleast in the recreational diving world.

Think about the medical world. So much analog/mechanical technology has been replaced by electronic/computer technology and we're talking about life support systems. I assume if they can keep a non breathing premature baby alive to grow up and live a full life with a computer they have a substantial amount of confidence in the reliability of their equipment. This is just one example.

This is the level of reliability I'm confident the dive industry can achieve. In my short time diving I've been quite impressed by the commitment of many manufactuers to create high quality reliable equipment and products. Perhaps I've just been exposed to so much cheap imported goods for so long now I'm happy/impressed to see some extremely well made thought out products.

---------- Post added January 12th, 2016 at 10:03 PM ----------

One issue I have had with the transmitters is that they make GREAT handles when handing up a scuba unit from the water into a small boat...I recently grabbed one and started pulling up, before I realized what I was holding.

I suspect it would not be too hard to rip one off... on accident ..say in the dark, when it is rough etc..

I had good luck with an air integrated computers, but they had hoses and I got them cheap and they worked for quite a while .. until they failed, but when deep on air, and doing deco (without any written plans) and solo and spearfishing, it is kinda nice to see an ascent time and an air time displayed. I never carried redundancy on the dive (other than a Casio G shock) ... on multiday trips, I always just bring a complete spare regulator ..

No doubt about that!!! I catch/stop myself from doing that a lot. Another reason why the units need to be smaller or build them from brass and chrome. Is there some reason they aren't made from brass?