Value of 4th Cell & Computer

ira

i think this is safer then, i use a stand alone vr3 and i dont like to have a 4th cell.

dive*ski

So most people seem to be using it for another PPO2 reading. How many are actually using it for calculating deco obligations ?

wedivebc

I personally feel the setpoint control on the meg is just fine and therefore don't see the need for the 4th cell. I also feel the K1D is less reliable (although I have only used them in a SK) than the R22Ds and so would be having to watch my deco PO2 as well as my loop PO2 even closer.
For me a fixed setpoint computer and good loop control works very well.

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Dave....

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nigelh

I have a fourth cell on the VR3.
It is only used as readout and the deco is run on selected setpoints.

Having had one run in with breaking the normal system on a shallow no-stop dive I decided that I needed a backup ppO2 display.

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nigelh

Depth-junkie

I use mine for deco calculations, as my vision is the basic timer and temp stick only (no int-deco) i did not want to pay the extra for the intgrated deco when i orderd my vision in 2005 as i had already owned a VR3 for 2yrs at that piont and it has never got me bent so i stuck with it.

I also run my unit semi alpine I.E redundant Dil and 02 (3ltrs straped to the box) and thats it no OC tins. The 4th cell gives me a redundant PO2 monitor as well as the 2 standard controlers and HUD. THe 4th cell adds to my get out of jail free so to speak.


I was asked to do a right up of how and why i run my unit as i do for YD by one of the mods on the board, here it is if your intersted:-

Alpine physco or not??? - YD Dive Forums & Scuba Community

ATB
Gareth







ATB
Gareth

Nemo1957

I use a 4th cell and a VR3 on my optima. I find that it simplifies my diving by having my PO2 instantly available to me whenever I look at the HUD or my VR3. Since the hammerheads scroll the PO2's you only have a 1 in 3 chance of having them present when you look at the HH if you arent lucky then you have to stare at your wrist until they scroll around. If the HUD and VR3 dont agree then I go to the HH handset for more detailed info on which cell is in question.

mverick

I had wanted a 4th cell. Got a VR3 in a trade. Didn't like the deco obligations. Bought a HS Explorer new. It never worked long enough to consider it.

I have a Old Shearwater on my Meg. First Generation. It's worked great. I will probably get another Shearwater, the Pursuit, when it's been out a while.

I don't want 4 handsets. To me, that's not why I dive. To have 4 different things to look at. Hud, Primary and Secondary Handsets, 4 Cell and handset. I love the Meg with the Shearwater. One Handset and a HUD. The HUD runs on it's own. It doesn't just repeat what the handset say's. So, it's like having 2. I wouldn't mind having another handset with a set setpoint. But having another wire I don't really want. If cochran would get there technology of wireless into a Rebreather. I'd be very interested. More snag points I don't want.

I just don't want a bunch of extra crap on me. That's the hole point. To minimize isn't it.

If you don't trust the system you have, time to get one you trust. If in doubt, bailout.

You can claim alpinist way. But, true alpinist way is not to carry extra junk either. It weighs you down.

Mdemon

I don't agree with that, but then I've never been afraid of carrying the kit. What works for you, works for you.

To answer the initial question, I have added a 4th cell and VR£ and the value was mixed. I didn't like it calculating my deco on it as it didn't always match the Inspo cells exactly. BUT! The main, and in my view ESSENTIAL value became apparent when a friend had a problem with his Classic which resulted in no PO2 monitoring from either handset and had to bail out. Learning from this, we now don't reboot both Classic handsets underwater.

However, if you have totally redundant PO2 monitoring then primary failure is less of a drama. Added benefits include sense-testing the values of new primary cells.

In my case, the 4th cell has gone, to be replaced by a 4th and 5th in the magnificent Beanie adapter and equally magnificent rEvoDream. Fixed setpoint deco on the VR£. Basically, there is no sensible reason for me to bailout from my Classic unless I get a total loop flood.

A friend of mine dives like this too and that's that - no stages, nothing. Alpinist but a qualified risk.

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Depth-junkie

What a load of shite, for the record my 4th cell gives me 1 vision handset showing info for both controlers, 1 HUD showing both controlers and a VR3 showing PO2 info.

Hardly weighed down with crap is it, far from it i have 2 things on my wrist 1x vision handset and 1x VR3 so i have no more bling on my wrist than you do with your meg, but i have way more options available than you do.


So no need to just bailout if my both controlers pack up or loss of handest etc etc, if the loops water tight i can finish the dive via the 4th cell. If its not water tight im fecked.

ATB
Gareth

mverick

Not really a load of shiite...

You now have 3 lines running to your arm/face.

I have 2. One wrapped around my hose for the HUD probably like you. And one running down my arm. Instead of 2. And I don't have one running down each arm.

Vision uses one handset to doesn't it? Not much different then the Original Shearwater Meg.

I carry bailout. Not an Alpinist.

And yea, you have more bling on your wrist. I have one shearwater handset and a HUD now. So, you have an extra cable and a VR3. In my post I said I didn't like the VR3 and the HSExplorer is a paperweight.

I've even run my handset ala Prism where I tie it off to my Dring and just run off my HUD. Nothing bound to my wrist. I would like it better if it was like the cochran and Wireless. Hard wire the HUD.

But, that's how I like to dive. As Unencombered as possible. Put a Bottom timer and tables in my pocket and I'm set.

I just pointed out why I didn't like it to the poster.

I know people who dive there MK15 and tables. Hmm.. There just looking to die. Clipped off secondary and Primary hud. Then tend to enjoy not having extra crap on them too.. Other then a bottom timer.