Triggering ADV

[rjack321]

Thanks for the link.

I don't think the megalodon is really measurable because the pressure on the Schrader valve is spread over a huge (and variable) area of counter lung. If I had a way to measure the kiss diaphragm I would.

I generally keep my adv shut off unless I am descending or scootering. 50mbar is 20 inches or 50cm of water. Both my units are almost for sure less tight than this.

 

[jgttrey]

My kiss has very limited capacity to adjust it. My Meg even less unless you dissect a schrader valve and somehow manipulate the strength of the tiny spring inside.

FWIW, you can also adjust/replace the "stem" of the plunger on the Meg ADV. The length of the stem determines how bottomed out the lungs have to be before it fires. ISC has a shorter one, or you can cut down the one you have.

Like you, I keep it cut off almost all the time, the shorter plunger mechanism does make it a bit less sensitive, but only a bit.

ISC was experimenting with a different ADV that had adjustable sensitivity that I got to beta-dive a couple of times and really liked, but I don't know if there's any plan to market it.

 

[rjack321]

FWIW, you can also adjust/replace the "stem" of the plunger on the Meg ADV. The length of the stem determines how bottomed out the lungs have to be before it fires. ISC has a shorter one, or you can cut down the one you have.

Like you, I keep it cut off almost all the time, the shorter plunger mechanism does make it a bit less sensitive, but only a bit.

ISC was experimenting with a different ADV that had adjustable sensitivity that I got to beta-dive a couple of times and really liked, but I don't know if there's any plan to market it.

I have the top of shoulder lungs which use a relatively long stem (longer than the normal stem at least). Its long enough that I can get the ADV to fire from water pressure alone when scootering fast if I am not careful. One reason I keep it off, also why I suspect its far less than 50mbar to trigger it.

 

[JohnnyC]

From what I can remember, the Megalodon has 3 plunger sizes, the "standard" for normal OTSCL's, a "short" for the neoprene lungs, and a "long" for the TOSCL's. Obviously swapping them out of their intended counterlungs will change their triggering behavior.

 

[rjack321]

From what I can remember, the Megalodon has 3 plunger sizes, the "standard" for normal OTSCL's, a "short" for the neoprene lungs, and a "long" for the TOSCL's. Obviously swapping them out of their intended counterlungs will change their triggering behavior.

yep this ^^^
you can cut them and rethread the remaining post too. But since all of these have a massive diaphragm (the CL) to trigger them I doubt any (with the correct plunger) take 50mbar of pressure to actuate.

 

[JohnnyC]

I k ow when I switched from normal OTSCL’s on my Meg to neo lungs, the adv was unusable with the stock plunger.

I ended up selling my Meg and picking up an SF2 so it ended up being a moot point.

 

[abnfrog]

I wouldn't go less than 3/4 inces of water column...or it will trigger too easy

 

[pesstrus]

Sorry for the late (4 year late) reply!
Still having the ADV set to around 50mbar, and still alive
Thanks for taking the time to reply to the post everyone

 

[Tracy]

Sorry for the late (4 year late) reply!
Still having the ADV set to around 50mbar, and still alive
Thanks for taking the time to reply to the post everyone

Mine is probably close to that. I keep it tuned tight as I don't like turning it off. I add manually 90% of the time. I use the ADV as a parachute if something bad is happening and I need a lung full of gas. I think turning it off defeats the purpose of having it.