Will Air Integration in dive computers replace the SPG?

[stuartv]

Funny - I have both dove with and around many J-Valves (Old diver here) including a J-Valve regulator (US Diver Calypso) I had. Lets see, the J valve was a mechanical spring prone to possible failure using a position that was prone to being bumped to the other position or even forget to being set. You typically had a metal bar coming down your harness that always got in the way. The pressure was sub 500 PSI that it would indicate which is not safe even for a deeper dive ascent. Even considering we did not do safety stops back then. So you would be comfortable doing an ascent from 125' with 500 PSI and a safety stop - oh and the restriction kicked in when you were on the other end of the wreck??? A bump could mean that you were at the regulator minimum and out of gas before you knew it. You would be comfortable doing your ascent from 125' with 200 PSI and a safety stop while still at the other end of the wreck????

So, basically, you didn't use to plan your dives. And you think that way of diving applies to a conversation about AI....?

Reliability and cost issues aside... (but not forgotten)...

AI could be useful for the technical diver if it provided a warning that compared available gas against planned dive and deco schedule. It'd be a purely baseline safeguard... as the tech diver should have plenty sufficient gas. Nonetheless, the unanticipated can occur and divers have been left with insufficient deco gas before.

Or, you could just put a transmitter on the right post of your backmount doubles and use it as an SPG. If nothing goes wrong, it's more convenient to check your pressure. If you end up shutting down the left post for some reason, then you still have an SPG.

You know, in case you have WAI for Rec diving anyway and you want to use it on your Tech rig, too.

And leave mechanical SPGs on all your other cylinders.

 

[Kevrumbo]

Sorry for asking .... could you explain it again?
I still haven't figure out on how to use it during a multi-level (with a lot of levels ....) dive

Given you are an advanced diver with a 1 bar/min per ATA pressure Surface Consumption Rate for a particular tank, then all you need for multi-levels are the depths in ATA, the time you spent at each multi-level depth, and then you can figure out your consumption for each particular depth, confirming it with an SPG or AI reading.

So you're at 30 meters depth; that's 4 ATA (30 divided-by 10 plus 1 equals 4 ATA); you stay 5 minutes. 1 bar/min per ATA multiplied by 4 ATA multiplied by 5 minutes equals 20 bar consumed. Confirm with SPG or AI, your delta remaining pressure reads 20 bar less --so if you start with a full tank of 200 bar, the SPG or AI should indicate "180 bar". (200 minus 20 is 180 bar).

You then ascend to 21 meters depth; that's 3.1 ATA (21 divided-by 10 plus 1 equals 3.1 ATA); you stay 10 minutes. 1 bar/min per ATA multiplied by 3.1 ATA multiplied by 10 minutes equals 31 bar consumed. Confirm with SPG or AI, your delta remaining pressure reads 31 bar less --SPG or AI should indicate "149 bar". (180 minus 31 is 149 bar).

You then ascend to 15 meters depth; that's 2.5 ATA (15 divided-by 10 plus 1 equals 2.5 ATA); you stay 30 minutes. 1 bar/min per ATA multiplied by 2.5 ATA multiplied by 30 minutes equals 75 bar consumed. Confirm with SPG or AI, your delta remaining pressure reads 75 bar less --SPG or AI should indicate "74 bar". (149 minus 75 is 74 bar).

Finally ascend to 6 meters depth; that's 1.6 ATA ( 6 divided-by 10 plus 1 equals 1.6 ATA); you stay 10 minutes. 1 bar/min per ATA multiplied by 1.6 ATA multiplied by 10 minutes equals 16 bar consumed. Confirm with SPG or AI, your delta remaining pressure reads 16 bar less --SPG or AI should indicate "58 bar". (74 minus 16 is 58 bar).

Do a slow ascent to the surface --on the surface inflate your BCD/Wing/Drysuit and you know even before looking at your SPG that you have 50 bar remaining in your tank.

With repetition, experience & persistent rote practice-- you will know what your SPG nominally reads at depth after an arbitrary time interval like five or ten minutes. Or, in the case of an AI, your total running gas remaining estimate over a five or ten minute interval should be similar to the algorithm's displayed value. The point is do not take for granted the calculations of AI --the features & functions of AI are ancillary to what you already know how to do in your head. . .

(If the expected SPG or AI reading is 30% or more than you figured, then that indicates you are physically working & breathing harder than normal, or have a leak somewhere in your reg/gear set-up, and should consider aborting the dive).

 

[The Chairman]

Some have petulantly demanded 'hard data',

Cry me a river! You come up with OtT crap like "written in blood" and tell the world how unsafe this is and yet no one, including you, can come up with a single solitary accident that is directly attributable to a faulty transmitter. Not even one! You call me petulant? We've just been FIGJAMmed again. You don't have any accidents to support your accident analysis that transmitters are dangerous. None, Nada and Squat! You have a fictitious problem in search of your rigid solution and you call me petulant? I was kind of fine with the whole discussion. I made my points and was content to leave it alone. But then you have to pull me back into it with this kind of FIGJAM. Perhaps you can complain to the mods about me "stalking" you again. Or, you can simply stop baiting me.

 

[Kevrumbo]

Cry me a river! You come up with OtT crap like "written in blood" and tell the world how unsafe this is and yet no one, including you, can come up with a single solitary accident that is directly attributable to a faulty transmitter. Not even one! You call me petulant? We've just been FIGJAMmed again. You don't have any accidents to support your accident analysis that transmitters are dangerous. None, Nada and Squat! You have a fictitious problem in search of your rigid solution and you call me petulant? I was kind of fine with the whole discussion. I made my points and was content to leave it alone. But then you have to pull me back into it with this kind of FIGJAM. Perhaps you can complain to the mods about me "stalking" you again. Or, you can simply stop baiting me.

Okay, Netdoc, we need some officiating. I have gone back and counted the number of times Kev has explained his methodology of using data from an SPG. We have seen it explained 13 times and I figure that may actually be some sort of record? Even after I pointed out that he has no audience for what may be a perfectly legitimate system he continues to go out there swinging. I will give him props for determination (or OCD?).

I remember when I was a new teacher and I came up with a lesson that tanked and I would be stuck teaching it over and over..... because for that one topic, I was a one band.

You teach best what you need most to learn. . .

You never learned it and you're both lousy teachers.

 

[kelemvor]

battery in the wrong way which screwed up the circuit, etc. My WAI has a big warning about putting the battery in wrong.

I'm surprised a manufacturer would design a circuit so badly. A single diode would completely solve that problem and probably would cost less than printing the warning label.

I've often wondered about the engineering prowess of some scuba manufacturers. I think a lot are just making minor modifications to another's design without any real understanding of what they are doing. Things like you report make me more confident that this is the case.

On the bright side, it means that there is probably lots of low hanging fruit with regards to technical improvements in scuba equipment.

 

[lowviz]

I'm surprised a manufacturer would design a circuit so badly. A single diode would completely solve that problem and probably would cost less than printing the warning label.

Yes, and a four diode bridge would mean the battery could go in in either direction as long as you can tolerate the drop in voltage due to the diodes.

On the bright side, it means that there is probably lots of low hanging fruit with regards to technical improvements in scuba equipment.

Totally agree.

A tank of compressed gas contains an awesome amount of energy, Waaaaay too much to use to its full capacity. The tiniest bit of this could be used to keep resupplying a battery on every breath. I could see a tiny spinner consisting of rare earth magnets that are driven by tank pressure gas as it just enters the primary reg. The spinner jams, no prob. HP gas just flows around it. Now, you don't need to use fancy ass high-energy batteries, you can back down to the good old proven reliable types. Just like the alternator in your car working with a box of sulfuric acid and lead, or the space station.

So who will be the first regulator manufacturer to offer a high pressure port with a stable control voltage as an equipment option?

 

[Eric Sedletzky]

Yes, and a four diode bridge would mean the battery could go in in either direction as long as you can tolerate the drop in voltage due to the diodes.
Totally agree.

A tank of compressed gas contains an awesome amount of energy, Waaaaay too much to use to its full capacity. The tiniest bit of this could be used to keep resupplying a battery on every breath. I could see a tiny spinner consisting of rare earth magnets that are driven by tank pressure gas as it just enters the primary reg. The spinner jams, no prob. HP gas just flows around it. Now, you don't need to use fancy ass high-energy batteries, you can back down to the good old proven reliable types. Just like the alternator in your car working with a box of sulfuric acid and lead, or the space station.

So who will be the first regulator manufacturer to offer a high pressure port with a stable control voltage as an equipment option?

Wow, I never thought of that. What a cool idea.

 

[lowviz]

Thanks, man.

Best part, it is now PUBLIC DOMAIN. They can all scramble for the loose ball if there is any merit to it.

 

[Centrals]

A tank of compressed gas contains an awesome amount of energy, Waaaaay too much to use to its full capacity. The tiniest bit of this could be used to keep resupplying a battery on every breath. I could see a tiny spinner consisting of rare earth magnets that are driven by tank pressure gas as it just enters the primary reg. The spinner jams, no prob. HP gas just flows around it. Now, you don't need to use fancy ass high-energy batteries, you can back down to the good old proven reliable types. Just like the alternator in your car working with a box of sulfuric acid and lead, or the space station.

So who will be the first regulator manufacturer to offer a high pressure port with a stable control voltage as an equipment option?

Tiny amount to drive the Bourdon gauge and the rest for breathing or whatnot(bc, dry suit etc).

 

[lowviz]

Just for clarity, I'd like to make a fundamental stand on MY intent:

The term “public domain” refers to creative materials that are not protected by intellectual property laws such as copyright, trademark, or patent laws. The public owns these works, not an individual author or artist. Anyone can use a public domain work without obtaining permission, but no one can ever own it.

See: http://fairuse.stanford.edu/overview/public-domain/welcome/

This work is dedicated to the public domain!

Undo that one, lawyers...