Which Computer for SCR and CCR?

[caveseeker7]

Hi again, FLTEK.

1 . Uwatec Aladin Air Z-O2 Hoseless Wrist Computer , and you also need the OXY 2 ... I don't even think it's upgradable to CCR, and can you switch gases underwater for deco stops?

The combo was originally developed for the Dolphin's predecessor, the Atlantis, and is therefor a perfect fit. The Oxy2 actually has two cells, so there is some redundancy. The algorithm is Bühlmann's, that a bit outdated. Most of Uwatec's computers have been updated to microbubble algorithms, this is not one of them. It only claculates air and nitrox mixes, no helium, and calculates based on a fraction of oxygen (mix) rather than setpoint/pO2.
It doesn't work reliably with CCRs, this letter posted at Rebreathers Worlwide explains why.
TecMe as well as TechBlue sell adapters that will connect the Oxy2 into the loop of the Azimuth.

2. HS Explorer ...

3. Delta VR3 ... an adapter from Delta P for SCR? cost?

Both will do up to 10 gas mixes, including He based ones.
Both can calculate fO2 and pO2, both will work OC, SC and CC.
Both can be used with a CCR with or without an O2 sensor in the loop.
For both you'll need a connector (most likely Dräger's P-port, though there are others like the new one from TecMe that sits in the same spot as the Oxy2).
Both had problems early on, the Explorer with cases and the VR3 with the buttons.
Both problems have been taken care of.
Both have manuals available for download on the manufacturer's websites. Good way to check out features and procedures for switching modes & gases, setting them up etc.

The main difference is the algorithms used, the Explorer uses true RGBM, the VR3 Bühlmann with microbubbles. The VR3 is slated for an update to VPM-B next spring, which should make it pretty much equal to the Explorer.

A few questions is i heard the VR3's for a while everyone was ebaying them cause they were so hard to use..... any help here would be appreciated.

The VR3 prompts the functions of its two buttons on the bottom of the screen which I think is extremely helpfull. Either one will likely be a handfull when new.

Im leaning towards the VR3, did they come out with a VR4

Haven't heard anything about a VR4 when I talked to Kevin and Tamara at DEMA. The latest updates were in the software as well as the available color screen, and an optional contends gauge connection for OC.

There is a VR2, a 4 gas mixes Nitrox only version of the VR3. It has a composite case rather than metal, but OC, SC and CC versions with integrated O2 cell are available.

I want a computer that will grow with me, using both in SCR and CCR, switchable gases upto 100% O2 underwater for deco, moniter PPO2, and do everything else in between, i know im going to spend around $1,300 for a computer, so i don;t want to buy somthing this year, and sell it in 6 months or a year when i goto CCR and be limited, and loose money.

Currently only the VR3 and Explorer offer the features listed above. They'll grow as far as one probably can.

Cochran has computers that offer OC/CC including He, but not cell integrated (currently, they used to have the Lifeguard with that feature). I also don't know if they work for SCRs as they lack the cell.

AP Valves offers the Buddy dive computer that works OC and CC with nitrox only (4 OC mixes I believe), not integrated nor SC.

Stefan

PS: Terence, have a look at Philippe Gerin's Azimuth CCR conversion on Rebreathers Worldwide.

 

[hornetplt]

I have the VR3 attached via a Drager P-port(along with an HS Explorer) in exhalation lung. The way I made my Azimuth a "manual constant CCR," is by turning down the adjustable mass flow controller to a value of 1.4-1.6 lpm and run approx 75% NITROX in bottom tank. This will give me a steadily decreasing ppO2 when VO2 > .7 lpm. I manually add gas as my ppO2 drops below the set point I intend to use. The top tank is used for diluent until I reach my intended operating depth, I then isolate the top tank(via a switch) and turn on the bottom tank. The 2 ppO2 sensors are the BARE minimum and about all I have room for with 2 seperate Drager P-ports. It works well, but a rig intended for CCR works MUCH better. Save the money and buy a CCR!! All the advise you read from all the other posts WRT saving $ and waiting for CCR purchase is VERY good advice. Trust me! I just kicked myself again! Azimuth = $4500 VR3 w/ppO2 CCR = $1300, HS Explorer ppO2 = $550.......total w/p-ports, etc = $6500......for a unit that was not made to do this and requires even more vigilence. VR3 SCR mode gives O2 as a Nx value (i.e. 40% whether at 10 feet or 150 feet), CCR gives you ppO2, which you must have if you indend to operate under CCR principles, or have a dive slate with the Nx conversion = not recommended!
I sincerely hope this helps!
Brian

 

[Life-Is-Good-Diver]

VR3. http://www.vr3.co.uk/ You may wish to search the boards for other discussions of which computer...

You can also get some bits from DeltaP to integrate the vr3 to several units on the market and there are other folks out there making adapters for additional units, http://www.tecme.de/frame_eq2.htm .

Don't screw around with the Uwatec it will be a paper weight if you move to a ccr. Even if you ultimately upgrade to a CCR with an integrated deco computer, a VR3 is a hell of a back-up unit.

The VR3 looks incredibly difficult when you initially view their interface screens on their web site, it is however very intuitive when you are actually diving it. It also providesyou with the most flexibility of any of the computers I am aware of. I have never dived the Explorer and plenty of RB divers use them, I imagine you will hear from them.

Doug

Thanks Doug, i backed away from the Uwatec, seems to be more of a rec computer, and would only be good as long as i stayed with SCR, which i know im not, the VR3 is looking great, as well as the HS explorer, ive basicalley narrowed it down to those to, for now,

 

[Life-Is-Good-Diver]

I have the VR3 attached via a Drager P-port(along with an HS Explorer) in exhalation lung. The way I made my Azimuth a "manual constant CCR," is by turning down the adjustable mass flow controller to a value of 1.4-1.6 lpm and run approx 75% NITROX in bottom tank. This will give me a steadily decreasing ppO2 when VO2 > .7 lpm. I manually add gas as my ppO2 drops below the set point I intend to use. The top tank is used for diluent until I reach my intended operating depth, I then isolate the top tank(via a switch) and turn on the bottom tank. The 2 ppO2 sensors are the BARE minimum and about all I have room for with 2 seperate Drager P-ports. It works well, but a rig intended for CCR works MUCH better. Save the money and buy a CCR!! All the advise you read from all the other posts WRT saving $ and waiting for CCR purchase is VERY good advice. Trust me! I just kicked myself again! Azimuth = $4500 VR3 w/ppO2 CCR = $1300, HS Explorer ppO2 = $550.......total w/p-ports, etc = $6500......for a unit that was not made to do this and requires even more vigilence. VR3 SCR mode gives O2 as a Nx value (i.e. 40% whether at 10 feet or 150 feet), CCR gives you ppO2, which you must have if you indend to operate under CCR principles, or have a dive slate with the Nx conversion = not recommended!



I sincerely hope this helps!

Brian

Very much so !!! Great point on the cost starting out in SCR, i thought ALOT about it, and the Azimuth ranging cost around $4,800.00 and the sport kiss ranging around $5000, for myself, i would have to go with CCR only to fit the needs of diving i will be doing withen the next year or so, but for now, i thought i would pick up a SCR unit for around $2k slightey used, and get some experiance and fit the budget.

By the time i add on the HS or VR3, the SCR unit, A new dry suit ( DUI ) and a few other things i need, im sure i'll be around 5k, with training, so that should keep me bubble less for the next year till i can go into CCR,

Dam, i can't wait, which i just had $7k laying around the house, better yet i asked the wife if she can get it for me for X-mas, i sealed the deal, but instead of costing me $7k for CCR, it cost me $45k as she want's her BMW, so it's back to SCR for now ,lol

 

[caveseeker7]

... but instead of costing me $7k for CCR, it cost me $45k as she want's her BMW, so it's back to SCR for now ,lol

For now, yes, but that beemer ought to by you some lattitude for the future.

 

[Life-Is-Good-Diver]

For now, yes, but that beemer ought to by you some lattitude for the future.

LOL, thanks for all your help Stephan, like always your post are great, and very helpfull, thanks again

 

[DiveTub]

Just sold a Uwatec AirZ O2 on Ebay, used it with my Dolphin that has now also been sold.

I now dive with a VR3 for everything OC, SCR and CCR. Wished I had picked it up years ago. Does everything I will ever need from a computer and strong enough to hammer nails.

I could teach a monkey to use the interface on the VR3 in 20 minutes, once you understand it you can navigate round with your eyes closed. Anyone that has trouble using a VR3 should really go back to pre-school and not go near a any sort of ECCR.

Cheers
Chris

 

[Life-Is-Good-Diver]

Just sold a Uwatec AirZ O2 on Ebay, used it with my Dolphin that has now also been sold.

I now dive with a VR3 for everything OC, SCR and CCR. Wished I had picked it up years ago. Does everything I will ever need from a computer and strong enough to hammer nails.

I could teach a monkey to use the interface on the VR3 in 20 minutes, once you understand it you can navigate round with your eyes closed. Anyone that has trouble using a VR3 should really go back to pre-school and not go near a any sort of ECCR.

Cheers
Chris

Hey thanks Chris, i had a bid on the Uwatec, but backed out, as i pretty much to go with the VR3 also, i had the HS explorer, awsome computer, but after talking to A few friends that dive the VR3, and researching it, ive pretty much made up my mind....can't wait !!!