Oxyguage and MCCR Dolphin

HooKeTePoo · 9th October 2006, 00:24

Just noticed some comments on the Oxyguage not being a good computer to use for a Dolphin MCCR but there were no details to why.... ?

Captain Randy · 9th October 2006, 00:52

Quote: (Originally Posted by HooKeTePoo)

Just noticed some comments on the Oxyguage not being a good computer to use for a Dolphin MCCR but there were no details to why.... ?

It is safer to use a 3 cell O2 monitor since you will be injecting your O2
with 3 cells you can see a cell going bad (not matching the other 2) and
still be able to see whats in your loop.

Randy

HooKeTePoo · 9th October 2006, 01:00

Quote: (Originally Posted by Captain Randy)

It is safer to use a 3 cell O2 monitor since you will be injecting your O2
with 3 cells you can see a cell going bad (not matching the other 2) and
still be able to see whats in your loop.

Randy

Thanx Randy, I found an old thread with some info on the oxyguage as well, it calculates on Fo2 not the Po2.. I think in a year when I'm ready to convert I'll get a Vr3 color for the conversion.

RonMicjan · 9th October 2006, 01:31

well first an oxygauge is not a dive computer, just a one cell po2 monitor. I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin.

The system uses 2 cells and averages the output and will tell you when a cell is out of range, but not give you the data for each cell, so in effect its like diving a single cell readout, no redundancy, fine for SCR dolphin, but not for CCR where you may need to verify one cell against another.

the primary reason why the unit sucks for CCR diving is the way the deco algorithm works. the system is expecting you to be on a SCR and that you will have a minimum PO2 near the surface and a maximum PO2 at depth, and a constant Fo2, exactly the reverse of how a constant PO2 CCR works, where you have a maximum Fo2 of oxygen at the surface and minimum at depth. where this becomes the problem is when the dive computer sees your Fo2 fall at depth, it assumes that you are working very hard using up all the O2 in the loop (on an scr, this is what happens when you work hard, the bag Fo2 falls) so it increases your deco obligation thinking your metabolic rate is very high, then it wont give you much credit when you come shallow and your fo2 is back up, cause now you are resting and off gassing slowly.

I did several dives on this computer when I first converted my dolphin to CCR and wondered why the alarms kept going off and why I was so far off my constant PO2 CCR dive tables. I soon went to a tied in explorer dive computer and my bottom times extended significantly. Later I did some diving with Dave from BC and he was using the same uwatec stuff I had abandoned, we were finding 30+ minutes of deco difference between his computer and mine.

the VR3 dive computer has an SCR mode, that does the look ahead based on a constant FO2, if you use this mode while on CCR your real deco will run out much faster than the projection. But you will find the inverse true if you dive SCR while in CCR mode, the look ahead will be expecting a constant PO2 and your SCR will be delivering a constant Fo2. There is some discussion of the difference between constant PO2 diving and constant Fo2 in my article rebreather math, here

hope this helps and my assumtion on which item you have is correct too

**wedivebc** · 9th October 2006, 01:44

Quote: (Originally Posted by HooKeTePoo)

Thanx Randy, I found an old thread with some info on the oxyguage as well, it calculates on Fo2 not the Po2.. I think in a year when I'm ready to convert I'll get a Vr3 color for the conversion.

If you indeed have an oxygauge then it measures ppo2. The only down side to it is it has a habit of flooding. The Oxy2 that Ron described above still measures PPO2 but also uses a depth measurement to convert the reading to FO2. It was after one very long deco on the Cape Breton when Ron had cleared his VR3 about 25 minutes before my AirZO2 cleared that I decided to change my PPO2 monitoring.
I did find 2 PPO2 monitors to be sufficient since any discrepencies between PPO2 displays could be resolved with a dil flush.

HooKeTePoo · 7th November 2006, 04:59

Quote: (Originally Posted by RonMicjan)

I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin.

Ron,
Yup, right on! I had an origional airZ O2 with the unit, on my checkout dive, Err Mode!! Damnit! The first time I have it up and running it bombs. So I found a used AirX O2 from Yevgeniy on RBW and I'm looking foward to diving the unit 1st time when I get back into austin!!

Matt H
AkA:Switch

JonORunde · 7th November 2006, 10:43

The main problem with this computer, is that it will not show correct deco-info when diving mCCR. It still works good as a ppO2-meter, showing accummulated info from two cells -so I have been diving with it, and either used tables with constant ppO2 or a VR3 with its own cell. So -just using it for the cells.
Problem then, is if you get a lot of deco (it stops counting at 99 minutes !

-at least doesn't show more then 99... ) When you follow the tables/VR3, you will blow of a lot of deco given to you by the uwatec, and it gets very mad -> goes into ERR-mode for 48 hous or so... -So only one such dive, and a very long break before the next one. And no -It does not show O2-info when in ERR_mode...

For SCR on the other hand -excellent! (anyone wants to buy a used one?)

Jon O

jknights · 7th November 2006, 19:20

Quote: (Originally Posted by RonMicjan)

well first an oxygauge is not a dive computer, just a one cell po2 monitor. I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin.

The system uses 2 cells and averages the output and will tell you when a cell is out of range, but not give you the data for each cell, so in effect its like diving a single cell readout, no redundancy, fine for SCR dolphin, but not for CCR where you may need to verify one cell against another.

the primary reason why the unit sucks for CCR diving is the way the deco algorithm works. the system is expecting you to be on a SCR and that you will have a minimum PO2 near the surface and a maximum PO2 at depth, and a constant Fo2, exactly the reverse of how a constant PO2 CCR works, where you have a maximum Fo2 of oxygen at the surface and minimum at depth. where this becomes the problem is when the dive computer sees your Fo2 fall at depth, it assumes that you are working very hard using up all the O2 in the loop (on an scr, this is what happens when you work hard, the bag Fo2 falls) so it increases your deco obligation thinking your metabolic rate is very high, then it wont give you much credit when you come shallow and your fo2 is back up, cause now you are resting and off gassing slowly.

I did several dives on this computer when I first converted my dolphin to CCR and wondered why the alarms kept going off and why I was so far off my constant PO2 CCR dive tables. I soon went to a tied in explorer dive computer and my bottom times extended significantly. Later I did some diving with Dave from BC and he was using the same uwatec stuff I had abandoned, we were finding 30+ minutes of deco difference between his computer and mine.

the VR3 dive computer has an SCR mode, that does the look ahead based on a constant FO2, if you use this mode while on CCR your real deco will run out much faster than the projection. But you will find the inverse true if you dive SCR while in CCR mode, the look ahead will be expecting a constant PO2 and your SCR will be delivering a constant Fo2. There is some discussion of the difference between constant PO2 diving and constant Fo2 in my article rebreather math, here

hope this helps and my assumtion on which item you have is correct too

Very interesting stuff, Ron.
I've been using the Air Z O2 and Oxy2 on my mCCR Submatix but also use a VR3 and single P-Ported cell as a cross check.

I really want to move to a three cell unit that measures visa the P-Port adapter.
Any suggestions for alternatives. I like what Scuba_Vixen has done (see this forum) and am tempted to follow this route as a want a triple O2 cell unit with each cell output showing. I know the Mark Munro unit is about but I want something more along the lines of the OxyPic OxyPic

Any suggestions ?

Stephane · 7th November 2006, 19:42

Hello,

Quote:

Any suggestions ?

Yes, you should have a look at Paul Raymaeker's rEvodream, a two cell PpO2 meter with a HUD.
For the moment there is only a CCR version but soon Paul will release a SCR version (air and O2 calibration, wider usable PpO2 range).
Pictures of the rEvodream can be seen here: http://www.rebreatherworld.com/photo...er/397/cat/500

OK, that's only two cells but you have a VR3 for the third one.

Divein · 7th November 2006, 20:12

I'm in the process of converting to mCCR. Had a look at the Revodream but there is also Mark Munroe's DIY - I think Martin at Tecme has started selling those here. Plus there is also Subsea Systems here and Sartek found here. Does anyone know of any other alternatives?

I'm favouring the Revodream at the moment but I too will need to sell my Oxy2 and Air Z O2.

9th October 2006, 00:24	#1 (permalink)
HooKeTePoo New Member Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jun 2006 Location: Austin Tx Posts: 19	Oxyguage and MCCR Dolphin Just noticed some comments on the Oxyguage not being a good computer to use for a Dolphin MCCR but there were no details to why.... ?
(Offline)

9th October 2006, 00:52	#2 (permalink)
Captain Randy New Member Current Rebreather/s: Dolphin Ray Other Rebreather/s: Dolphin Ray Join Date: Dec 2005 Location: Houston, Texas Posts: 45	Re: Oxyguage and MCCR Dolphin Quote: (Originally Posted by HooKeTePoo) Just noticed some comments on the Oxyguage not being a good computer to use for a Dolphin MCCR but there were no details to why.... ? It is safer to use a 3 cell O2 monitor since you will be injecting your O2 with 3 cells you can see a cell going bad (not matching the other 2) and still be able to see whats in your loop. Randy
(Offline)

9th October 2006, 01:00	#3 (permalink)
HooKeTePoo New Member Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jun 2006 Location: Austin Tx Posts: 19	Re: Oxyguage and MCCR Dolphin Quote: (Originally Posted by Captain Randy) It is safer to use a 3 cell O2 monitor since you will be injecting your O2 with 3 cells you can see a cell going bad (not matching the other 2) and still be able to see whats in your loop. Randy Thanx Randy, I found an old thread with some info on the oxyguage as well, it calculates on Fo2 not the Po2.. I think in a year when I'm ready to convert I'll get a Vr3 color for the conversion.
(Offline)

9th October 2006, 01:31	#4 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,119	Re: Oxyguage and MCCR Dolphin well first an oxygauge is not a dive computer, just a one cell po2 monitor. I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin. The system uses 2 cells and averages the output and will tell you when a cell is out of range, but not give you the data for each cell, so in effect its like diving a single cell readout, no redundancy, fine for SCR dolphin, but not for CCR where you may need to verify one cell against another. the primary reason why the unit sucks for CCR diving is the way the deco algorithm works. the system is expecting you to be on a SCR and that you will have a minimum PO2 near the surface and a maximum PO2 at depth, and a constant Fo2, exactly the reverse of how a constant PO2 CCR works, where you have a maximum Fo2 of oxygen at the surface and minimum at depth. where this becomes the problem is when the dive computer sees your Fo2 fall at depth, it assumes that you are working very hard using up all the O2 in the loop (on an scr, this is what happens when you work hard, the bag Fo2 falls) so it increases your deco obligation thinking your metabolic rate is very high, then it wont give you much credit when you come shallow and your fo2 is back up, cause now you are resting and off gassing slowly. I did several dives on this computer when I first converted my dolphin to CCR and wondered why the alarms kept going off and why I was so far off my constant PO2 CCR dive tables. I soon went to a tied in explorer dive computer and my bottom times extended significantly. Later I did some diving with Dave from BC and he was using the same uwatec stuff I had abandoned, we were finding 30+ minutes of deco difference between his computer and mine. the VR3 dive computer has an SCR mode, that does the look ahead based on a constant FO2, if you use this mode while on CCR your real deco will run out much faster than the projection. But you will find the inverse true if you dive SCR while in CCR mode, the look ahead will be expecting a constant PO2 and your SCR will be delivering a constant Fo2. There is some discussion of the difference between constant PO2 diving and constant Fo2 in my article rebreather math, here hope this helps and my assumtion on which item you have is correct too __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job Last edited by RonMicjan : 9th October 2006 at 01:34.
(Offline)

9th October 2006, 01:44	#5 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,508	Re: Oxyguage and MCCR Dolphin Quote: (Originally Posted by HooKeTePoo) Thanx Randy, I found an old thread with some info on the oxyguage as well, it calculates on Fo2 not the Po2.. I think in a year when I'm ready to convert I'll get a Vr3 color for the conversion. If you indeed have an oxygauge then it measures ppo2. The only down side to it is it has a habit of flooding. The Oxy2 that Ron described above still measures PPO2 but also uses a depth measurement to convert the reading to FO2. It was after one very long deco on the Cape Breton when Ron had cleared his VR3 about 25 minutes before my AirZO2 cleared that I decided to change my PPO2 monitoring. I did find 2 PPO2 monitors to be sufficient since any discrepencies between PPO2 displays could be resolved with a dil flush. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
(Online)

7th November 2006, 04:59	#6 (permalink)
HooKeTePoo New Member Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jun 2006 Location: Austin Tx Posts: 19	Re: Oxyguage and MCCR Dolphin Quote: (Originally Posted by RonMicjan) I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin. Ron, Yup, right on! I had an origional airZ O2 with the unit, on my checkout dive, Err Mode!! Damnit! The first time I have it up and running it bombs. So I found a used AirX O2 from Yevgeniy on RBW and I'm looking foward to diving the unit 1st time when I get back into austin!! Matt H AkA:Switch
(Offline)

7th November 2006, 10:43	#7 (permalink)
JonORunde New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2005 Location: Norway Posts: 88	Re: Oxyguage and MCCR Dolphin The main problem with this computer, is that it will not show correct deco-info when diving mCCR. It still works good as a ppO2-meter, showing accummulated info from two cells -so I have been diving with it, and either used tables with constant ppO2 or a VR3 with its own cell. So -just using it for the cells. Problem then, is if you get a lot of deco (it stops counting at 99 minutes ! -at least doesn't show more then 99... ) When you follow the tables/VR3, you will blow of a lot of deco given to you by the uwatec, and it gets very mad -> goes into ERR-mode for 48 hous or so... -So only one such dive, and a very long break before the next one. And no -It does not show O2-info when in ERR_mode... For SCR on the other hand -excellent! (anyone wants to buy a used one?) Jon O
(Offline)

7th November 2006, 19:20	#8 (permalink)
jknights New Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: May 2005 Location: Oliva, Valencia, Spain. Posts: 121	Re: Oxyguage and MCCR Dolphin Quote: (Originally Posted by RonMicjan) well first an oxygauge is not a dive computer, just a one cell po2 monitor. I believe you may be asking about an Oxy2 with an AirZ O2 wireless dive computer made by Uwatec for the dolphin. The system uses 2 cells and averages the output and will tell you when a cell is out of range, but not give you the data for each cell, so in effect its like diving a single cell readout, no redundancy, fine for SCR dolphin, but not for CCR where you may need to verify one cell against another. the primary reason why the unit sucks for CCR diving is the way the deco algorithm works. the system is expecting you to be on a SCR and that you will have a minimum PO2 near the surface and a maximum PO2 at depth, and a constant Fo2, exactly the reverse of how a constant PO2 CCR works, where you have a maximum Fo2 of oxygen at the surface and minimum at depth. where this becomes the problem is when the dive computer sees your Fo2 fall at depth, it assumes that you are working very hard using up all the O2 in the loop (on an scr, this is what happens when you work hard, the bag Fo2 falls) so it increases your deco obligation thinking your metabolic rate is very high, then it wont give you much credit when you come shallow and your fo2 is back up, cause now you are resting and off gassing slowly. I did several dives on this computer when I first converted my dolphin to CCR and wondered why the alarms kept going off and why I was so far off my constant PO2 CCR dive tables. I soon went to a tied in explorer dive computer and my bottom times extended significantly. Later I did some diving with Dave from BC and he was using the same uwatec stuff I had abandoned, we were finding 30+ minutes of deco difference between his computer and mine. the VR3 dive computer has an SCR mode, that does the look ahead based on a constant FO2, if you use this mode while on CCR your real deco will run out much faster than the projection. But you will find the inverse true if you dive SCR while in CCR mode, the look ahead will be expecting a constant PO2 and your SCR will be delivering a constant Fo2. There is some discussion of the difference between constant PO2 diving and constant Fo2 in my article rebreather math, here hope this helps and my assumtion on which item you have is correct too Very interesting stuff, Ron. I've been using the Air Z O2 and Oxy2 on my mCCR Submatix but also use a VR3 and single P-Ported cell as a cross check. I really want to move to a three cell unit that measures visa the P-Port adapter. Any suggestions for alternatives. I like what Scuba_Vixen has done (see this forum) and am tempted to follow this route as a want a triple O2 cell unit with each cell output showing. I know the Mark Munro unit is about but I want something more along the lines of the OxyPic OxyPic Any suggestions ?
(Offline)

7th November 2006, 19:42	#9 (permalink)
Stephane Stéphane Acounis Current Rebreather/s: rEvo Other Rebreather/s: rEvo Join Date: Nov 2005 Location: Nantes - France Posts: 788	Re: Oxyguage and MCCR Dolphin Hello, Quote: Any suggestions ? Yes, you should have a look at Paul Raymaeker's rEvodream, a two cell PpO2 meter with a HUD. For the moment there is only a CCR version but soon Paul will release a SCR version (air and O2 calibration, wider usable PpO2 range). Pictures of the rEvodream can be seen here: http://www.rebreatherworld.com/photo...er/397/cat/500 OK, that's only two cells but you have a VR3 for the third one. __________________ Stéphane
(Online)

7th November 2006, 20:12	#10 (permalink)
Divein RBW Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Jun 2006 Location: Yorkshire Posts: 107	Re: Oxyguage and MCCR Dolphin I'm in the process of converting to mCCR. Had a look at the Revodream but there is also Mark Munroe's DIY - I think Martin at Tecme has started selling those here. Plus there is also Subsea Systems here and Sartek found here. Does anyone know of any other alternatives? I'm favouring the Revodream at the moment but I too will need to sell my Oxy2 and Air Z O2.
(Online)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode