Will Air Integration in dive computers replace the SPG?

[Centrals]

When an SPG is out of calibration, a diver will still be able to use it, with no way of knowing that it has failed until he starts sucking rust when the gauge is reading 400 psi. A transponder will fail catastrophically and the diver will know he has a failure and can abort the dive.

You are not suggesting that electronic will not give you wrong information!

 

[CT-Rich]

I have heard of transmitters failing (usually battery failure), but of it the sensor transmitting incorrect data? Have you ever heard of an AI system that reporting a tank having 400 psi when it was actually empty? I have seen SPG that were out of calibration. Keep in mind that from a mechanical standpoint their are more failure point on a traditional SPG than there are on AI sensor (o-rings, hose, hose connections, etc...). A battery failure simply means you have no data. A burst hose means you are losing gas (although not necessarily in a catastrophic way). are either of these life threatening failures? or are they annoyances? I think the loss of data on my wrist would be less annoying. When the equipment is cheap enough and reliable enough you will see most new divers adopting it out of the gate and when people want to go tech they will go to the corner of the shop that has all the tech toys and buy the traditional SPG.

 

[CT-Rich]

Will computer's ever supplant simple reliable mechanical gauges? What do you think runs your car?

 

[Patoux01]

I have heard of transmitters failing (usually battery failure), but of it the sensor transmitting incorrect data? Have you ever heard of an AI system that reporting a tank having 400 psi when it was actually empty?

I don't hang around AI enough to have seen that. However, pressure sensors in computers fail every now and then, giving either frozen or completely off readings. No reason to think it cannot happen on the transmitters. (although they're not the same sensors)

 

[stuartv]

How to quantify that threat?

If something is diagnosable pre-dive, then is it a major threat? In contrast, if something is most likely to fail in-water, with no prior warning and no means to diagnose potential failure in advance... is that the more major threat?

In respect to technology advances in diving; I'd much rather see the design effort turned towards improving safety/reliability of existing components. If someone improved, say, materials technology in o-rings, or connection design. I'd like to see an improvement to LPI designs.... mask and fin straps fail... why do manufacturers not embrace alternatives as a standard?

Do you diagnose an impending failure inside your SPG pre-dive?

AI is an electronic SPG.

If you want to see design effort turned towards improving safety/reliability of existing components, then I would have thought you'd be ecstatic to see all the effort going into replacing mechanical SPGs with electronic ones.

The electronic ones seem to have close to nil chance of causing you to lose gas when they fail. An SPG certainly can't say that. And the electronic SPG has 1 static O-ring to fail. The SPG has at least 3. The electronic SPG has one threaded connection that could come loose. The mechanical has two.

The list of mechanical things that have been replaced with more reliable, safer, electronic versions is ridiculously long. Why would anyone not see SPGs as inevitably being on that same list?

The electronic SPG has a lot less failure points. It's less likely to result in loss of gas if it does fail (at least, I think). It's more convenient to use. It gives the user more/better data. It's hugely more precise (notice I made no assertion about accuracy, though I suspect that they are more accurate, too, in general, after some time in service).

And the current crop seems to be just as reliable as a mechanical SPG (assuming proper maintenance of both). Can any of you that keep asserting that electronic SPGs are less reliable provide data (that is even somewhat current) to back that claim up?

To the poster who talked about having to recharge AI, I have to ask HUHH?!?!? I haven't seen any AI transmitters that are anything but a battery that you change once a year or so. I think my Oceanic transmitter says a battery is good for 300 hours. It's over a year old and when I check the transmitter battery status on my computer it still says "Good". I will keep using it until the computer warns me of a transmitter low battery, or it just dies. If it happens to just die during a dive (which seems extremely unlikely compared to going to use it and finding it to be dead before I even get in the water), oh, well. Worst case, I thumb the dive because my SPG has died. But, I'm reasonably confident that if the battery is low enough to die during the dive, the computer will give me a transmitter low battery warning before I get in.

 

[stuartv]

30 years ago, I used a corded home telephone - they never failed..

Just curious, what did you use 30 years ago to tell you your depth?

Also, which is more important for you to know - your depth or your tank pressure?

And, do you require all your students to have a mechanical depth gauge as a backup to their computer?

 

[Charles2]

Fifty years ago I dove with a mechanical depth gauge, a magnetic/mechanical compass, a mechanical watch rated to 300 ft. with a rotating bezel, a mechanical J-valve and planned my dives with Navy dive tables while using mathematics on a note pad to calculate my gas consumption. It was the 'cat's meow' and I lived. It was all I needed because it was all that was available to a teenager who paid for everything with earnings from a job at the local grocer. I am often tempted to avow that all that tradition, unhampered by progress, is still worthy. But it just ain't so. I bought my first computer about two years ago (I've always been slow and cheap). It does everything that all those mechanical devices used to do, except that it is probably more accurate and is definitely quicker. When any of the mechanical devices of yesteryear failed (they never did), I ended the dive and followed my bubbles to the surface. If my computer fails (it never has) I will end the dive and follow my bubbles to the surface. I love to dive.

Edit: Oh yeah, I had a big ass knife strapped to my leg.

 

[Bennno]

Just curious, what did you use 30 years ago to tell you your depth?

Also, which is more important for you to know - your depth or your tank pressure?
And, do you require all your students to have a mechanical depth gauge as a backup to their computer?

Depth is a different story, the computer needs to your depth to give your NDL or your stops. AI doesn't give you anything, it's a toy. The 'rest air time' value is BS.
Having depth measured electronically has benefits, measuring pressure electronically doesn't. Why do you pro AI guys think it hasn't caught on in 20 years?
If you like it, go for it, it's not gonna kill you, but you gotta admit it's a toy.

 

[agilis]

Thirty years ago I used a mechanical depth gauge. I still do. I have a computer, but I rely on the mechanical gauge. It's just plain superior, just like the SPG. Computers are useful for no deco calculations and when diving a jagged profile. Otherwise, it's too many numbers on too many screens, a plastic gizmo.

Computers in cars can be annoying. I like carburetors, rotors, points, timing lights; honest straightforward technology that I can work on myself.

 

[stuartv]

Depth is a different story, the computer needs to your depth to give your NDL or your stops. AI doesn't give you anything, it's a toy. The 'rest air time' value is BS.
Having depth measured electronically has benefits, measuring pressure electronically doesn't. Why do you pro AI guys think it hasn't caught on in 20 years?
If you like it, go for it, it's not gonna kill you, but you gotta admit it's a toy.

It hasn't caught on because it wasn't reliable enough. Maybe it is now.

If it's okay to depend on an electronic instrument for depth, which is vital, why is it not just as okay to depend on an electronic instrument for pressure?

My pressure gauge is not a toy to me! For sport dives, my electronic gauge is my only pressure gauge. It's not a toy and, so far, nobody has given any hard data to support the notion that CURRENT AI technology is less reliable than an SPG (assuming proper maintenance of both).

Once cost comes down on the AI transmitters to, say, $100, why would any recreational sport dive that is buying their own computer and regulators choose a mechanical gauge? My computer cost $550, including a transmitter and USB cable. Should I have bought a different computer and a mechanical SPG?