New Prism Diver in Marina Del Rey, Calif.

ChettL

caveseeker7

Hi Chett, didn't get a chance to say hello in your intro thread, so welcome to Rebreather World.

The number of dive computers that can calculate deco with a set pO2 are limited,
some allow calculating with the actual pO2 by adding an additional O2 cell to the loop.

Non-integrated pO2 deco computers:
- Buddy Nexus (least expensive afaIk, but no He)
- Cochran (several models, He optional)

Integrated pO2 deco computers:
- DeltaP VR2 (normoxic trimix option)
- DeltaP VR3 (trimix option)
- Hydrspace Explorer (trimix)

- not out yet is the Dive Rite Nitek X (trimix)

For the PRISM W+S Water Safety in Germany makes a cell holder that replaces the elbow on
the inhalation bag, measuring the pO2 just before it gets to the DSV.
All of the integrated computers use different cells than the PRISM, so you'll have to buy
different sensors from different suppliers and they can't be interchanged.
The integrated computers can also operate with a pre-set O2 value rather than reading
the actual gas in the loop.

There are also three dive computers that can read and calculate with all three cells:
The Shearwater GF, the DeltaP Universal Rebreather Monitor and the Juergensen Marine Hammerhead.
I don't know if any of these can operate with the PRISM's high output sensors, though.
The highest probabilty would have to be the Juergensen Hammerhead secondary,
as the Hammerhead is available for the MK15/MK15.5 series that also uses high output cells.
You would have to ask Kevin (heydude here at Rebreather World) about that.
Hooking any of them up though would likely require drilling into the head.

If you use the search function in the top bar with any of the models mentioned above
you'll find plenty of threads, discussions, good and bad experiences.
Or just read through the threads in the Rebreather Electronics/Computer forum.

From what I've seen the Explorer is quite popular with PRISM users, probably because it
uses an RGBM algorithm. Steam Machines has RGBM tables, as does NAUI through which many
PRISM divers are certified. Furthermore Steam Machines has been working on an integrated
dive computer on and off for a while now which should use the same algorithm.
Wouldn't hold my breath for that one though.

Have also seen VR3s and Cochrans ebing used, don't recall ever seeing anyone
(at all, anywhere with any rig, ever) using either a Buddy Nexus or a VR2.

__________________
Cheers
Stefan


Be Water, My Friend - Bruce Lee

Sponsor Lou in Race For Life!

silent running

Hi ChettL, congratulations on the Prism and welcome to Rebreather World.

Stefan very thoroughly covered the info in regarding the computer comparisions. I've had both the VR3 and HE, no problems with either. I prefer the RGBM algorhythm on the HE for tmix, so that's the one I have now. My advice is to go with the unit which is manufactured closest to your home to make customer service as easy as possible and also to think about which deco alg makes the most sense to you. Good luck to you and your computer, -Andy