Using AI with surface supplied "hookah" systems

[high_order1]

I really think that computer-assisted diving is the smart move. I don't think it is a complete replacement for understanding dive physics and common sense, but if you are not being a tourist (ie scrubbing hulls or the like), having a meter keep a weather eye on your status is smart.

My impression of the AI systems, especially ones that do heart rate monitoring, is that they can do calculations based on the pressure drop of the tank.

Surface-supplied low pressure air (obviously) isn't the same pressures the typical AI systems are looking for. I suspect if you plumbed a transmitter into such a system, it would panic thinking you are completely out of air.

Said all that to say this: I can't find where anyone cares enough to put a gauge on a hookah system. I think having the air integrated into the dive computer might be smart if you were going to be at say ten feet for several hours over several days. I think I understand how to put a manual gauge at the divers' end on such a setup, but has someone already figured out how to do this with an air integrated wrist mount computer?

(understand that this is more of a notional concept rather than something I intend to implement immediately)

 

[Cthippo]

Interestimg concept. The enabling tech all exists, but you would need to integrate it and write the software.

Basically AI is really just an underwater communication protocol. The sender unit measures a value (tank pressure) and transmits that data to a reciever (dive computer) that displays it. The same protocol could be used for other measurements.

 

[high_order1]

Thank you. I was reading a guide book the United Nations put out on safe hookah diving, and looking at dive computers. One computer says it can handle ten transmitters in real time, and you can switch tanks and it just knows, probably by the pressure drop.

So, I thought, I've read on here almost all of you use at least one digital computer, some more. What's available for the hookah guys? I recognize they generally don't go deep. But reading that UN booklet, some people are down shallow for a long, long time harvesting or cleaning weeds or doing other things. It all seems like a math problem, and perhaps if it is your job ten hours a day 6 days a week, that low pressure of depth coupled with double digit exposure times...

That book talks about getting bent (if you have joint aches...). So, seems like there is a need.

I suspect you are correct, in that it would require a firmware correction. 'low pressure mode? Y/N'

I simply wondered if someone had already tested this past saying, well, if you can't breathe, there's no air left (which isn't the point). Or that the computer would just make assumptions without having gauge pressure available (infinite dive time remaining at this depth). Don't know what I don't know, and didn't see an answer.

 

[TooCold]

I haven't done it (and never used a hookah system) but ... what you want to do seems easier than you think (I think).

But maybe I'm not understanding exactly what your goal is? Why not just plumb an AI transmitter into your air line within range of your wrist? Job done. No hardware, firmware, software mods necessary. If your computer "panics" then I'd say you need a different computer.

I know this works just fine with Shearwater AI computers. I did something similar when trying to work out the AI transmitter encoding a couple of years ago. I hooked up a transmitter to my shop compressor (10 bar - same ballpark as regulator IP). I could then slowly bleed the pressure and watch the transmitted signal to look for bits counting down. All of that is irrelevant to what you want to do but the point is the transmitter turns on and stays on at a low enough pressures to work just fine when hooked up to a system at IP pressures like a hookah system.

IIRC with MH8A transmitters turn-on was about 100 psi and turn-off at about 20 psi. Using a Shearwater computer all you'll notice is the pressure display is yellow or red to indicate low or very low pressure, but no alerts, alarms, or other panic.

Here's a picture. Yes, I just used hose clamps and regular shop hose instead of hunting for proper adapters/fittings, since it was just for shop experiments and at these low low pressures.

 

[runsongas]

It sounds like you want it to be able to let you know the hookah compressor is working correctly to give you a warning if it shuts off. but AI generally would not be useful in this case due to the distance limitations and that the accuracy would mean you would have to wait until the reserve tank starts dropping below 100 psi with the compressor not working before you would see a difference which gives a small window of usefulness over just feeling the WOB increase.

 

[Zef]

Sigh.

-Z

 

[tursiops]

I really think that computer-assisted diving is the smart move. I don't think it is a complete replacement for understanding dive physics and common sense, but if you are not being a tourist (ie scrubbing hulls or the like), having a meter keep a weather eye on your status is smart.

My impression of the AI systems, especially ones that do heart rate monitoring, is that they can do calculations based on the pressure drop of the tank.

Surface-supplied low pressure air (obviously) isn't the same pressures the typical AI systems are looking for. I suspect if you plumbed a transmitter into such a system, it would panic thinking you are completely out of air.

Said all that to say this: I can't find where anyone cares enough to put a gauge on a hookah system. I think having the air integrated into the dive computer might be smart if you were going to be at say ten feet for several hours over several days. I think I understand how to put a manual gauge at the divers' end on such a setup, but has someone already figured out how to do this with an air integrated wrist mount computer?

(understand that this is more of a notional concept rather than something I intend to implement immediately)

Why do you want to monitor the pressure in the hookah line? How will you use that information?
Isn't that pressure constant if the hookah is working correctly, and goes to zero almost immediately if the hookah system fails?
I assume by hookah you mean a compressor at the surface thst id feeding the approx 140psi into the line going to the second-stage regulator in the mouth of the diver?

 

[high_order1]

Why do you want to monitor the pressure in the hookah line? How will you use that information?
Isn't that pressure constant if the hookah is working correctly, and goes to zero almost immediately if the hookah system fails?

What I am building will have a reserve / pulse flattening tank. Add that to what's in the line, and I am unsure about pressures at depth and exertion. I would prefer more actionable data than, well, I think I am breathing harder. Hm. LOL

My thought at the time was... the computer wanted the data to better calculate bottom time and nitrogen. Also, I want the user experience to be the same between hookah and scuba. I don't want to fall out of the habit of monitoring the pressure gauge because there isn't one in most underwater supplied air systems that I have surveyed. Everyone seems to be of the 'well, I am out of air so I will terminate by standing up'.

I haven't done it (and never used a hookah system) but ... what you want to do seems easier than you think (I think).

But maybe I'm not understanding exactly what your goal is? Why not just plumb an AI transmitter into your air line within range of your wrist? Job done. No hardware, firmware, software mods necessary. If your computer "panics" then I'd say you need a different computer.

I know this works just fine with Shearwater AI computers. I did something similar when trying to work out the AI transmitter encoding a couple of years ago. I hooked up a transmitter to my shop compressor (10 bar - same ballpark as regulator IP). I could then slowly bleed the pressure and watch the transmitted signal to look for bits counting down. All of that is irrelevant to what you want to do but the point is the transmitter turns on and stays on at a low enough pressures to work just fine when hooked up to a system at IP pressures like a hookah system.

IIRC with MH8A transmitters turn-on was about 100 psi and turn-off at about 20 psi. Using a Shearwater computer all you'll notice is the pressure display is yellow or red to indicate low or very low pressure, but no alerts, alarms, or other panic.

Here's a picture. Yes, I just used hose clamps and regular shop hose instead of hunting for proper adapters/fittings, since it was just for shop experiments and at these low low pressures.

That is something I was trying to determine. Because it's not a normal condition, none of the things I reviewed disclosed if they would go to sleep under a certain PSI. Thank you!

It sounds like you want it to be able to let you know the hookah compressor is working correctly to give you a warning if it shuts off. but AI generally would not be useful in this case due to the distance limitations and that the accuracy would mean you would have to wait until the reserve tank starts dropping below 100 psi with the compressor not working before you would see a difference which gives a small window of usefulness over just feeling the WOB increase.

I agree. I had thoughts of a simple electrical circuit at the pump, but then because I wanted the pump to cycle (working through what I had found about duty cycles), it would alarm so much as to be useless.

Basically, I wanted an air integrated computer because it seemed like it was better for determining uncommon SCUBA dive profiles. It sees you are breathing harder. I picked one that also monitors skin temp and heart rate, because at the time, it seemed prudent.

I wasn't certain how the computer would deal with diving on an air profile and not seeing the AI sensor. Perhaps it locks up for safety? I also am not sure how it will behave when it sees basically an empty, last breath tank.

Dunno, I am innovating.

What I do know about are surface supplied air systems. They generally just use a whistle at the user end to warn about transient low air (and kinked hose / trouble) anomalies. I need to go look and see if any have a gauge at the users' end.

To be transparent, the main reason I don't have a test article ready for the pool is because I am kind of decision paralyzed on filtration. I have seen a MONSTROUS delta in how this is addressed. From none at all to a thousand dollar multiple stage device.

Anyway, thanks for all the input!

 

[happy-diver]

I didn't know those computer things calculated dcs probability on heart rate, air remaining and tank pressure

The things I don't know, is that what's going on here

Enquiring minds are good

 

[high_order1]

I didn't know those computer things calculated dcs probability on heart rate, air remaining and tank pressure

The things I don't know, is that what's going on here

Enquiring minds are good

Yes, mostly. I suppose I could have taken the YMCA Dive Computer course, but learning from people that actually have suffered seems to give me better results.

If one can believe the marketing:

As far as what it does with tank pressure / remaining, I still am learning, hence this line of questioning here. Assumption was that it would get increasingly nanny on me. Apparently, this may not be the case.

I continue to try and solve my lack of apnea computing, perhaps I will share my results in another post. I would not have bought this one as my entry-level basic unit had I known how out of support it was.