VR3 Bailout question

PCDiver · 10th May 2006, 12:00

I have a question about bailout.

Scenario: I'm diving my Inspiration with HH. I run into a major electronic problem and both handsets are not usable. I go to SCR mode. I have three (actually 4) gasses available: diluent, bottom gas, deco gas and oxygen. I have connectors for all off-board gasses, so I can use them in SCR mode.

My question is, how do I configure my VR3? The VR3 is not plugged into the loop.

Thanks,

Peter

divetheworld · 10th May 2006, 12:24

Quote: (Originally Posted by PCDiver)

I have a question about bailout.

Scenario: I'm diving my Inspiration with HH. I run into a major electronic problem and both handsets are not usable. I go to SCR mode. I have three (actually 4) gasses available: diluent, bottom gas, deco gas and oxygen. I have connectors for all off-board gasses, so I can use them in SCR mode.

My question is, how do I configure my VR3? The VR3 is not plugged into the loop.

Thanks,

Peter

There is no easy bail out option. This is something we have long since been asking for

.
You would have to program in the bail in your gas list and turn each one on when you blow. It might be easier to pre-program those into another profile and switch profiles when this occurrs.

Brent

PCDiver · 10th May 2006, 12:30

Quote: (Originally Posted by divetheworld)

There is no easy bail out option. This is something we have long since been asking for

.
You would have to program in the bail in your gas list and turn each one on when you blow. It might be easier to pre-program those into another profile and switch profiles when this occurrs.

Brent

But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.

decoweenie · 10th May 2006, 12:40

Quote: (Originally Posted by PCDiver)

But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.

Bump up the conservatism to compensate.

Padowan · 10th May 2006, 12:40

Quote: (Originally Posted by PCDiver)

But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.

You're right, but OC is the closest that the VR3 has to offer. One alternative is to determine the OC FO2 equivalent of the SCR gas for a given gas, breathing cycle, etc... and then program this in as an OC gas in the VR3 - I have a spreadsheet that can work this out. PM me your address and I can forward it to you if you like...

Simon

decoweenie · 10th May 2006, 12:45

Quote: (Originally Posted by Padowan)

...I have a spreadsheet that can work this out...

Or generate the % of O2 reduction empirically.

Turn O2 valve off, go SCR and note the displayed PO2 -> determine the fiO2 on the xth breath.

divetheworld · 10th May 2006, 12:50

Quote: (Originally Posted by PCDiver)

But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.

Thats absolutely right. That is what I was thinking (but didnt write!) when I suggested another profile as the gas list is limited to ten gases. The SCR inspired gases would be dissimilar to the raw gas in the cylinder (another gas list).
For your dive you would need most of the available gases, for SCR bail you would need to program in the expected loop gas o2. I also would put a couple of team based gases in. This may exceed the ten gases, its also a pain in the ass to turn on all those gases for the look ahead deco information.

Personally I wouldnt be happy to take scr mode into account for a return to base plan. I would use it as a stop gap whilst at a constant depth because of the hypoxia risk is too much for me to be comfortable with even with air as Dil. With other gas mixes I just wouldnt consider it for the upward journey.
Under the circumstances of having gone to SCR for a spell my backup plans are conservative enough that a short spell is tollerable without having to switch to dynamic tables. I would use OC to 6m then if the loop was functional (without leccy's) I would flush and go to O2 CCR.

If you need to calc your fo2 in SCR mode try reading this -> http://www.imagedive.com.au/vsc/vsc.htm
There is a spreadsheet at the bottom, also V-planner can give you a nice bail plan taking into account dynamic fo2's.
Does that make sense?

Brent

PCDiver · 10th May 2006, 13:25

Quote: (Originally Posted by divetheworld)

Thats absolutely right. That is what I was thinking (but didnt write!) when I suggested another profile as the gas list is limited to ten gases. The SCR inspired gases would be dissimilar to the raw gas in the cylinder (another gas list).
For your dive you would need most of the available gases, for SCR bail you would need to program in the expected loop gas o2. I also would put a couple of team based gases in. This may exceed the ten gases, its also a pain in the ass to turn on all those gases for the look ahead deco information.

Personally I wouldnt be happy to take scr mode into account for a return to base plan. I would use it as a stop gap whilst at a constant depth because of the hypoxia risk is too much for me to be comfortable with even with air as Dil. With other gas mixes I just wouldnt consider it for the upward journey.
Under the circumstances of having gone to SCR for a spell my backup plans are conservative enough that a short spell is tollerable without having to switch to dynamic tables. I would use OC to 6m then if the loop was functional (without leccy's) I would flush and go to O2 CCR.

If you need to calc your fo2 in SCR mode try reading this -> http://www.imagedive.com.au/vsc/vsc.htm
There is a spreadsheet at the bottom, also V-planner can give you a nice bail plan taking into account dynamic fo2's.
Does that make sense?

Brent

Crystal clear. Thanks guys.

Drmike · 10th May 2006, 14:54

Quote: (Originally Posted by PCDiver)

But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.

Program the SCR gas with a lower FO2 than the actual 'OC' gas you are using.

How much lower depends on your met. and the way you run semiclosed. Best bet is to practice running semiclosed (with O2 off) and look at your handsets after a while to determine what your equivalent FO2 will be for each mix.

This I believe is part of a CCR trimix course - at least it was part of mine

[sorry forgot - nothing to learn on ccr trimix course right

]

PCDiver · 10th May 2006, 15:17

Quote: (Originally Posted by Drmike)

How much lower depends on your met. and the way you run semiclosed.
This I believe is part of a CCR trimix course - at least it was part of mine

[sorry forgot - nothing to learn on ccr trimix course right

]

It also depends on the bailout gas you are breathing. And the total loop volume. And the loop volume between the injection point and the cells. And ....

I just wanted to get a feeling for what value other divers are using.

Quote: (Originally Posted by Drmike)

This I believe is part of a CCR trimix course - at least it was part of mine

[sorry forgot - nothing to learn on ccr trimix course right

]

Please, let's not go there. BTW, I will do my CCR Trimix course (eventually)

Simon - Great spreadsheet. It also clearly shows why air diluent is a no-no when shallow.

10th May 2006, 12:00	#1 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	VR3 Bailout question I have a question about bailout. Scenario: I'm diving my Inspiration with HH. I run into a major electronic problem and both handsets are not usable. I go to SCR mode. I have three (actually 4) gasses available: diluent, bottom gas, deco gas and oxygen. I have connectors for all off-board gasses, so I can use them in SCR mode. My question is, how do I configure my VR3? The VR3 is not plugged into the loop. Thanks, Peter
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10th May 2006, 12:24	#2 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,636	Re: VR3 Bailout question Quote: (Originally Posted by PCDiver) I have a question about bailout. Scenario: I'm diving my Inspiration with HH. I run into a major electronic problem and both handsets are not usable. I go to SCR mode. I have three (actually 4) gasses available: diluent, bottom gas, deco gas and oxygen. I have connectors for all off-board gasses, so I can use them in SCR mode. My question is, how do I configure my VR3? The VR3 is not plugged into the loop. Thanks, Peter There is no easy bail out option. This is something we have long since been asking for . You would have to program in the bail in your gas list and turn each one on when you blow. It might be easier to pre-program those into another profile and switch profiles when this occurrs. Brent __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe
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10th May 2006, 12:30	#3 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: VR3 Bailout question Quote: (Originally Posted by divetheworld) There is no easy bail out option. This is something we have long since been asking for . You would have to program in the bail in your gas list and turn each one on when you blow. It might be easier to pre-program those into another profile and switch profiles when this occurrs. Brent But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower.
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10th May 2006, 12:40	#4 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: VR3 Bailout question Quote: (Originally Posted by PCDiver) But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower. Bump up the conservatism to compensate.
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10th May 2006, 12:40	#5 (permalink)
Padowan RBW Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Exeter, UK. Posts: 526	Re: VR3 Bailout question Quote: (Originally Posted by PCDiver) But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower. You're right, but OC is the closest that the VR3 has to offer. One alternative is to determine the OC FO2 equivalent of the SCR gas for a given gas, breathing cycle, etc... and then program this in as an OC gas in the VR3 - I have a spreadsheet that can work this out. PM me your address and I can forward it to you if you like... Simon __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
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10th May 2006, 12:45	#6 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: VR3 Bailout question Quote: (Originally Posted by Padowan) ...I have a spreadsheet that can work this out... Or generate the % of O2 reduction empirically. Turn O2 valve off, go SCR and note the displayed PO2 -> determine the fiO2 on the xth breath.
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10th May 2006, 12:50	#7 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,636	Re: VR3 Bailout question Quote: (Originally Posted by PCDiver) But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower. Thats absolutely right. That is what I was thinking (but didnt write!) when I suggested another profile as the gas list is limited to ten gases. The SCR inspired gases would be dissimilar to the raw gas in the cylinder (another gas list). For your dive you would need most of the available gases, for SCR bail you would need to program in the expected loop gas o2. I also would put a couple of team based gases in. This may exceed the ten gases, its also a pain in the ass to turn on all those gases for the look ahead deco information. Personally I wouldnt be happy to take scr mode into account for a return to base plan. I would use it as a stop gap whilst at a constant depth because of the hypoxia risk is too much for me to be comfortable with even with air as Dil. With other gas mixes I just wouldnt consider it for the upward journey. Under the circumstances of having gone to SCR for a spell my backup plans are conservative enough that a short spell is tollerable without having to switch to dynamic tables. I would use OC to 6m then if the loop was functional (without leccy's) I would flush and go to O2 CCR. If you need to calc your fo2 in SCR mode try reading this -> http://www.imagedive.com.au/vsc/vsc.htm There is a spreadsheet at the bottom, also V-planner can give you a nice bail plan taking into account dynamic fo2's. Does that make sense? Brent __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Last edited by divetheworld : 10th May 2006 at 13:01.
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10th May 2006, 13:25	#8 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: VR3 Bailout question Quote: (Originally Posted by divetheworld) Thats absolutely right. That is what I was thinking (but didnt write!) when I suggested another profile as the gas list is limited to ten gases. The SCR inspired gases would be dissimilar to the raw gas in the cylinder (another gas list). For your dive you would need most of the available gases, for SCR bail you would need to program in the expected loop gas o2. I also would put a couple of team based gases in. This may exceed the ten gases, its also a pain in the ass to turn on all those gases for the look ahead deco information. Personally I wouldnt be happy to take scr mode into account for a return to base plan. I would use it as a stop gap whilst at a constant depth because of the hypoxia risk is too much for me to be comfortable with even with air as Dil. With other gas mixes I just wouldnt consider it for the upward journey. Under the circumstances of having gone to SCR for a spell my backup plans are conservative enough that a short spell is tollerable without having to switch to dynamic tables. I would use OC to 6m then if the loop was functional (without leccy's) I would flush and go to O2 CCR. If you need to calc your fo2 in SCR mode try reading this -> http://www.imagedive.com.au/vsc/vsc.htm There is a spreadsheet at the bottom, also V-planner can give you a nice bail plan taking into account dynamic fo2's. Does that make sense? Brent Crystal clear. Thanks guys.
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10th May 2006, 14:54	#9 (permalink)
Drmike RBW Member Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,378	Re: VR3 Bailout question Quote: (Originally Posted by PCDiver) But you switch the VR3 to OC mode although you are in SCR mode. Isn't it an issue that you are breathing a gas with lower O2 content. First breath it is the same but by breath 4 the PPO2 is lower. Program the SCR gas with a lower FO2 than the actual 'OC' gas you are using. How much lower depends on your met. and the way you run semiclosed. Best bet is to practice running semiclosed (with O2 off) and look at your handsets after a while to determine what your equivalent FO2 will be for each mix. This I believe is part of a CCR trimix course - at least it was part of mine [sorry forgot - nothing to learn on ccr trimix course right ] __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 10th May 2006 at 14:57.
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10th May 2006, 15:17	#10 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: VR3 Bailout question Quote: (Originally Posted by Drmike) How much lower depends on your met. and the way you run semiclosed. This I believe is part of a CCR trimix course - at least it was part of mine [sorry forgot - nothing to learn on ccr trimix course right ] It also depends on the bailout gas you are breathing. And the total loop volume. And the loop volume between the injection point and the cells. And .... I just wanted to get a feeling for what value other divers are using. Quote: (Originally Posted by Drmike) This I believe is part of a CCR trimix course - at least it was part of mine [sorry forgot - nothing to learn on ccr trimix course right ] Please, let's not go there. BTW, I will do my CCR Trimix course (eventually) Simon - Great spreadsheet. It also clearly shows why air diluent is a no-no when shallow.
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