VR3 read out mix / po2 need help

David Parker · 17th December 2007, 23:04

Yeah watto there I finally finished my Drager conversion to MCCR & took it for its first run out today up at Stony. I have never dived a MCCR before & thought a bit of pionering wouldn't hurt. After replacing a few O rings to stopping the bubbles coming out of my first stage. I got to play on it "Fu$*ing awsome" Always loved my SCR but can understand why people love CC (20 bar of O2 used & about 5 Bar of Dill on 2 x 3ltr cyls) massive difference to my SCR with the 10L attached. I currently only have the 2 cells in it one on a VR3 & one independent. However all my VR3 shows is the mix & not the Po2, can this be changed what do I need to do to re con figure this if possible.

Cheers for the help
Dave

Hyper-limits · 17th December 2007, 23:53

You need to buy the CCR upgrade. I can't recall how much it is, probably around $175.00.

Cheers

Al

Dinspiration · 18th December 2007, 09:24

Hi

Or, if the VR3 is already CCR enabled you will need to switch the computer to CCR mode.....

Freak214 · 19th December 2007, 12:15

I remember how my first post conversion dive felt. That first dive is always a special one.

I assume everything went together without issue.

Glad to hear your first dive was a success!

JohnL

Numpty diver · 19th December 2007, 19:48

Any pictures of ya mean machine ?
Dean

David Parker · 28th December 2007, 20:10

Quote: (Originally Posted by Hyper-limits)

You need to buy the CCR upgrade. I can't recall how much it is, probably around $175.00.

Cheers

Al

If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ?

Cheers
Dave

ps i will try to sort some pics out....

camerone · 28th December 2007, 20:27

Quote: (Originally Posted by David Parker)

If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ?

Depends on whether you turn on either or both of the Xfunctions from the menu. You can either set it to constant PO2 (two set points, switchable easily with a long press), or set it to constant PO2 for lookups/deco calcs, but get the real-time data from the O2 sensor.

The CCR mode really adds three things, AFAIK (diving it for the last three years):

Readout in PO2 vs. %O2
Deco/NDL calcs based on constant PO2
Setting of PO2 versus %O2 in gas (as in, I'm breathing diluent #1, which is 21/35, but at a PO2 of 1.3, vs "21%")

You can run CCR with the VR3 in SCR mode, without buying the upgrade, and coupled to an external sensor, but what happens is that the look-ahead is basically screwed up. Your deco should clear at the same rate it would've on CCR, as your PO2 will climb, and it will factor this in (using the external cell) in burning off your time-at-stops, but it won't assume that as you ascend, you will ever elevate the %O2 in the loop. Instead, it'll use your fixed O2% breathing gas for the lookups, which you've likely preset to whatever the SCR O2 percentage is based on your source gas and metabolic rate.

You'll have to do the math in your head, too, to see if you're keeping the Rebreather at the right set point as you go up and down. That's not rocket science, but it is a pain.

So, without the CCR upgrade, it's more or less usable as an O2 monitor to make sure you've got a breathable loop, and it will get you out of the water safely, if the sensor works. You won't know how long, exactly, going in, but you'll know when you're done.

With the CCR upgrade (and an additional way of monitoring the loop %O2), if the external sensor fails on the VR3, you can still use it to get you out of the water appropriately, assuming you can maintain the fixed PO2 by other means.

I _guess_ you could fake CCR mode it by updating the O2% in your gas list at each stop in SCR mode, but that's a LOT of fiddling around...preset then turn on all ten gasses at the appropriate O2 percentages for each stop, and the VR3 will switch gasses for you

If you're really deep, and need more than 9 stops (plus bottom gas %O2) or multiple diluents, you'd be a little hosed, bad pun intended.

-c

Tienuts · 28th December 2007, 21:10

Quote: (Originally Posted by David Parker)

If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ?

The C2 (CC Nitrox) and C4 (CC Trimix) upgrades will enable your VR3 to calculate your tissue loading based on a constant PO2 value which you set on the VR3.

The C9 PIN, will activate the i/o port on the VR3, and give you the option of calculating tissue loading based on the reading that cell is providing the VR3.

You must have a C2 or C4 enabled VR3 to use the C9 upgrade.

David Parker · 29th December 2007, 23:39

Quote: (Originally Posted by Tienuts)

The C2 (CC Nitrox) and C4 (CC Trimix) upgrades will enable your VR3 to calculate your tissue loading based on a constant PO2 value which you set on the VR3.

The C9 PIN, will activate the i/o port on the VR3, and give you the option of calculating tissue loading based on the reading that cell is providing the VR3.

You must have a C2 or C4 enabled VR3 to use the C9 upgrade.

Cheers

David Parker · 4th January 2008, 12:01

Quote: (Originally Posted by Numpty diver)

Any pictures of ya mean machine ?
Dean

Yeah ear u go sorry with the delay, probably nothing you havent seen before. I also have kept the base strap so I can remove the dill & run it off my 10L for a bit of extra bail out on the deeper stuff.

17th December 2007, 23:04	#1 (permalink)
David Parker New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Not Bought Yet Dolphin Home Build Join Date: Jan 2006 Location: Essex Posts: 61	VR3 read out mix / po2 need help Yeah watto there I finally finished my Drager conversion to MCCR & took it for its first run out today up at Stony. I have never dived a MCCR before & thought a bit of pionering wouldn't hurt. After replacing a few O rings to stopping the bubbles coming out of my first stage. I got to play on it "Fu$*ing awsome" Always loved my SCR but can understand why people love CC (20 bar of O2 used & about 5 Bar of Dill on 2 x 3ltr cyls) massive difference to my SCR with the 10L attached. I currently only have the 2 cells in it one on a VR3 & one independent. However all my VR3 shows is the mix & not the Po2, can this be changed what do I need to do to re con figure this if possible. Cheers for the help Dave __________________ Fuzzy & Fat
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17th December 2007, 23:53	#2 (permalink)
Hyper-limits Al Delisle Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Apr 2006 Location: Victoria BC Canada Posts: 144	Re: VR3 read out mix / po2 need help You need to buy the CCR upgrade. I can't recall how much it is, probably around $175.00. Cheers Al __________________ "The oldest and strongest emotion of mankind is fear. And the oldest and strongest kind of fear is fear of the unknown" H.P. Lovecraft
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18th December 2007, 09:24	#3 (permalink)
Dinspiration Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Other CCR Join Date: Dec 2005 Location: Switzerland Posts: 209	Re: VR3 read out mix / po2 need help Hi Or, if the VR3 is already CCR enabled you will need to switch the computer to CCR mode.....
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19th December 2007, 12:15	#4 (permalink)
Freak214 New Member Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Jun 2005 Location: USA, Virginia Posts: 46	Re: VR3 read out mix / po2 need help I remember how my first post conversion dive felt. That first dive is always a special one. I assume everything went together without issue. Glad to hear your first dive was a success! JohnL
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19th December 2007, 19:48	#5 (permalink)
Numpty diver Custom Title Allowed! Current Rebreather/s: Megalodon Other CCR Dolphin Ray Home Build Other Rebreather/s: Other CCR Dolphin Ray Home Build Join Date: Jul 2006 Location: Norway, Bergen Posts: 210	Re: VR3 read out mix / po2 need help Any pictures of ya mean machine ? Dean
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28th December 2007, 20:10	#6 (permalink)
David Parker New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Not Bought Yet Dolphin Home Build Join Date: Jan 2006 Location: Essex Posts: 61	Re: VR3 read out mix / po2 need help Quote: (Originally Posted by Hyper-limits) You need to buy the CCR upgrade. I can't recall how much it is, probably around $175.00. Cheers Al If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ? Cheers Dave ps i will try to sort some pics out.... __________________ Fuzzy & Fat
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28th December 2007, 20:27	#7 (permalink)
camerone New Member Current Rebreather/s: Evolution Dolphin Other Rebreather/s: Dolphin Join Date: Oct 2005 Location: Seattle, WA Posts: 72	Re: VR3 read out mix / po2 need help Quote: (Originally Posted by David Parker) If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ? Depends on whether you turn on either or both of the Xfunctions from the menu. You can either set it to constant PO2 (two set points, switchable easily with a long press), or set it to constant PO2 for lookups/deco calcs, but get the real-time data from the O2 sensor. The CCR mode really adds three things, AFAIK (diving it for the last three years): Readout in PO2 vs. %O2 Deco/NDL calcs based on constant PO2 Setting of PO2 versus %O2 in gas (as in, I'm breathing diluent #1, which is 21/35, but at a PO2 of 1.3, vs "21%") You can run CCR with the VR3 in SCR mode, without buying the upgrade, and coupled to an external sensor, but what happens is that the look-ahead is basically screwed up. Your deco should clear at the same rate it would've on CCR, as your PO2 will climb, and it will factor this in (using the external cell) in burning off your time-at-stops, but it won't assume that as you ascend, you will ever elevate the %O2 in the loop. Instead, it'll use your fixed O2% breathing gas for the lookups, which you've likely preset to whatever the SCR O2 percentage is based on your source gas and metabolic rate. You'll have to do the math in your head, too, to see if you're keeping the Rebreather at the right set point as you go up and down. That's not rocket science, but it is a pain. So, without the CCR upgrade, it's more or less usable as an O2 monitor to make sure you've got a breathable loop, and it will get you out of the water safely, if the sensor works. You won't know how long, exactly, going in, but you'll know when you're done. With the CCR upgrade (and an additional way of monitoring the loop %O2), if the external sensor fails on the VR3, you can still use it to get you out of the water appropriately, assuming you can maintain the fixed PO2 by other means. I _guess_ you could fake CCR mode it by updating the O2% in your gas list at each stop in SCR mode, but that's a LOT of fiddling around...preset then turn on all ten gasses at the appropriate O2 percentages for each stop, and the VR3 will switch gasses for you If you're really deep, and need more than 9 stops (plus bottom gas %O2) or multiple diluents, you'd be a little hosed, bad pun intended. -c
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28th December 2007, 21:10	#8 (permalink)
Tienuts Chief Prankster Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2007 Location: Fort Lauderdale Posts: 221	Re: VR3 read out mix / po2 need help Quote: (Originally Posted by David Parker) If I buy the upgrade will it calculate on a constent PPO2 or will it continue to calculate everything off the O2 Cell ? The C2 (CC Nitrox) and C4 (CC Trimix) upgrades will enable your VR3 to calculate your tissue loading based on a constant PO2 value which you set on the VR3. The C9 PIN, will activate the i/o port on the VR3, and give you the option of calculating tissue loading based on the reading that cell is providing the VR3. You must have a C2 or C4 enabled VR3 to use the C9 upgrade.
(Offline)

29th December 2007, 23:39	#9 (permalink)
David Parker New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Not Bought Yet Dolphin Home Build Join Date: Jan 2006 Location: Essex Posts: 61	Re: VR3 read out mix / po2 need help Quote: (Originally Posted by Tienuts) The C2 (CC Nitrox) and C4 (CC Trimix) upgrades will enable your VR3 to calculate your tissue loading based on a constant PO2 value which you set on the VR3. The C9 PIN, will activate the i/o port on the VR3, and give you the option of calculating tissue loading based on the reading that cell is providing the VR3. You must have a C2 or C4 enabled VR3 to use the C9 upgrade. Cheers __________________ Fuzzy & Fat
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