VR3 in C4 mode, which setpoint?

Soren Thomsen · 12th May 2007, 16:32

Hi all,

Just wandered if those of you who are using VR3 with fixed setpoint choose the same setpoints on your VR3 as on the Rebreather.
Example to clarify if my english doesn't come out good enough:
Inspiration setpoints: 0.70 and 1.3
Do you run the VR3 with the same setpoint or do you choose 0.7 and 1.2 to make up for small differences?

Cheers
Soren

Silent · 12th May 2007, 17:47

I have my VR3 set for .05 below the setpoint I have on the Rebreather.

So for 98% of the time the VR3 is set at 1.25

Dinspiration · 12th May 2007, 17:50

Hi

If I'm using the system without a 4th cell connected I use the same setpoints on my VR3 and BI (Classic Electronic and HammerHead).

By the way: Do you know that you can preset two different setpoints on your VR3 as well (Page 39 of the manual)....

DINspiration

Mark Chase · 12th May 2007, 17:56

Quote: (Originally Posted by Silent)

I have my VR3 set for .05 below the setpoint I have on the Rebreather.

So for 98% of the time the VR3 is set at 1.25

As above

Unless its a monster dive 3H+ In which case id drop to 1.2

ATB

Mark Chase

Euge · 13th May 2007, 21:08

Agree with above

Normal stuff 0.65 and 1.25. (inspo at 0.7 and 1.3)

**nigelh** · 14th May 2007, 07:59

I set all the numbers to agree.

I apply my corrections to the results not half way through the chain.

Soren Thomsen · 14th May 2007, 11:45

Quote: (Originally Posted by nigelh)

I set all the numbers to agree.

I apply my corrections to the results not half way through the chain.

Hi Nigel,

Sorry, but I'm not sure I fully understand....(it's a language thing

)
I can see that you use same settings on VR3 according to Inspirations setpoints. So far so good.
Could you in an other way explain the last bit. Which correction do you apply and is it during the dive? How do you know how you are going to correct? and so on...

Cheers
Soren

divetheworld · 14th May 2007, 12:00

1.3 with no conservatism seems to agree with 15/85 on a vision?!?
Thats what one of my colleagues informs me for his dives anyway.

I use a different controller and set my VR3 to 0.7 and 1.25 with a conservatism of 10 on a bad day, none on a good day.
The best controllers use deco integration on all three cells which, (IMHO) negates the need for -0.05 settings but a backup should take into account sh1t happens. I suppose it depends on your diving styles, Scammahorn slides etc.
I dont reduce low setpoint because I cant remember the last time my PO2's read less than 1.0 other than waiting for more than a few mins on the surface.

Essentially you must ask the question, would you prefer to piss your buddy off by forcing him to complete another 8-10mins of stops or risk the pot?

Brent.

bourskov · 15th May 2007, 10:29

Hi Søren...

I'm also just diving it on the setpoints, so it's the same on my Inspo and my VR3. I'm quite new in rebreather diving, and therefore I'm not doing very deep dives yet. (Got my certificate in january this year). I remember my instructor told me to use the VR3 in this manner.

By the way, someone wrote something about pissing of a buddy, because of extra decotime!? My opinion to that is, if I'm doing a conservative diveplan, my buddy has to accept that. Like I have to accept it vice versa. Of course you can discuss how conservative you want do dive...

Last, but not least... If you are diving so close to the limit, so the slight variations between 1.25 and 1.3 is critical, then what about the CNS% and OTU ?! Correct me if I'm wrong, but if you lower the ppO2 on the VR3, the CNS% and OTU readings will also be wrong!?

Best regards
Bo Urskov

Johnny Christensen · 15th May 2007, 11:07

Quote: (Originally Posted by bourskov)

Last, but not least... If you are diving so close to the limit, so the slight variations between 1.25 and 1.3 is critical, then what about the CNS% and OTU ?! Correct me if I'm wrong, but if you lower the ppO2 on the VR3, the CNS% and OTU readings will also be wrong!?

Best regards
Bo Urskov

In the real world, the CNS and OTU are not all that important to track to the last decimal point... They are highly inacurate.

When looking at my PO2, I rarely have above 1,3 during the bottom portion of the dive. It tends to be 1,2 - 1,3. So the average value of 1,25 is closer to what you are actually doing.
But even when doing deep'ish and long dives, the few minutes extra in deco time won't make the difference between perfectly fine - or a serious bend.
It's a contributing factor, but 4-5 minutes out of 60-90 minutes obligations amounts to very little.

12th May 2007, 16:32	#1 (permalink)
Soren Thomsen Happy Hippo Current Rebreather/s: Not Bought Yet Other Rebreather/s: Inspiration Classic Not Bought Yet Join Date: Jan 2006 Location: Denmark Posts: 148	VR3 in C4 mode, which setpoint? Hi all, Just wandered if those of you who are using VR3 with fixed setpoint choose the same setpoints on your VR3 as on the Rebreather. Example to clarify if my english doesn't come out good enough: Inspiration setpoints: 0.70 and 1.3 Do you run the VR3 with the same setpoint or do you choose 0.7 and 1.2 to make up for small differences? Cheers Soren
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12th May 2007, 17:47	#2 (permalink)
Silent Staying Silent! Mostly... Current Rebreather/s: Other CCR Other Rebreather/s: Megalodon Ouroboros Other CCR Join Date: Jun 2005 Location: Northants, UK Posts: 383	Re: VR3 in C4 mode, which setpoint? I have my VR3 set for .05 below the setpoint I have on the Rebreather. So for 98% of the time the VR3 is set at 1.25
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12th May 2007, 17:50	#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: 207	Re: VR3 in C4 mode, which setpoint? Hi If I'm using the system without a 4th cell connected I use the same setpoints on my VR3 and BI (Classic Electronic and HammerHead). By the way: Do you know that you can preset two different setpoints on your VR3 as well (Page 39 of the manual).... DINspiration
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12th May 2007, 17:56	#4 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,540	Re: VR3 in C4 mode, which setpoint? Quote: (Originally Posted by Silent) I have my VR3 set for .05 below the setpoint I have on the Rebreather. So for 98% of the time the VR3 is set at 1.25 As above Unless its a monster dive 3H+ In which case id drop to 1.2 ATB Mark Chase __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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13th May 2007, 21:08	#5 (permalink)
Euge Euge Current Rebreather/s: Inspiration Classic Other Rebreather/s: Classic Kiss Join Date: Jun 2005 Location: UK Posts: 11	Re: VR3 in C4 mode, which setpoint? Agree with above Normal stuff 0.65 and 1.25. (inspo at 0.7 and 1.3)
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14th May 2007, 07:59	#6 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 821	Re: VR3 in C4 mode, which setpoint? I set all the numbers to agree. I apply my corrections to the results not half way through the chain. __________________ nigelh
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14th May 2007, 11:45	#7 (permalink)
Soren Thomsen Happy Hippo Current Rebreather/s: Not Bought Yet Other Rebreather/s: Inspiration Classic Not Bought Yet Join Date: Jan 2006 Location: Denmark Posts: 148	Re: VR3 in C4 mode, which setpoint? Quote: (Originally Posted by nigelh) I set all the numbers to agree. I apply my corrections to the results not half way through the chain. Hi Nigel, Sorry, but I'm not sure I fully understand....(it's a language thing ) I can see that you use same settings on VR3 according to Inspirations setpoints. So far so good. Could you in an other way explain the last bit. Which correction do you apply and is it during the dive? How do you know how you are going to correct? and so on... Cheers Soren
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14th May 2007, 12:00	#8 (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: 1,551	Re: VR3 in C4 mode, which setpoint? 1.3 with no conservatism seems to agree with 15/85 on a vision?!? Thats what one of my colleagues informs me for his dives anyway. I use a different controller and set my VR3 to 0.7 and 1.25 with a conservatism of 10 on a bad day, none on a good day. The best controllers use deco integration on all three cells which, (IMHO) negates the need for -0.05 settings but a backup should take into account sh1t happens. I suppose it depends on your diving styles, Scammahorn slides etc. I dont reduce low setpoint because I cant remember the last time my PO2's read less than 1.0 other than waiting for more than a few mins on the surface. Essentially you must ask the question, would you prefer to piss your buddy off by forcing him to complete another 8-10mins of stops or risk the pot? Brent. __________________ Self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe
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15th May 2007, 10:29	#9 (permalink)
bourskov New Member Current Rebreather/s: Ouroboros Other Rebreather/s: Inspiration Classic Join Date: Nov 2006 Location: Denmark Posts: 92	Re: VR3 in C4 mode, which setpoint? Hi Søren... I'm also just diving it on the setpoints, so it's the same on my Inspo and my VR3. I'm quite new in rebreather diving, and therefore I'm not doing very deep dives yet. (Got my certificate in january this year). I remember my instructor told me to use the VR3 in this manner. By the way, someone wrote something about pissing of a buddy, because of extra decotime!? My opinion to that is, if I'm doing a conservative diveplan, my buddy has to accept that. Like I have to accept it vice versa. Of course you can discuss how conservative you want do dive... Last, but not least... If you are diving so close to the limit, so the slight variations between 1.25 and 1.3 is critical, then what about the CNS% and OTU ?! Correct me if I'm wrong, but if you lower the ppO2 on the VR3, the CNS% and OTU readings will also be wrong!? Best regards Bo Urskov
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15th May 2007, 11:07	#10 (permalink)
Johnny Christensen Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2006 Location: Denmark Posts: 298	Re: VR3 in C4 mode, which setpoint? Quote: (Originally Posted by bourskov) Last, but not least... If you are diving so close to the limit, so the slight variations between 1.25 and 1.3 is critical, then what about the CNS% and OTU ?! Correct me if I'm wrong, but if you lower the ppO2 on the VR3, the CNS% and OTU readings will also be wrong!? Best regards Bo Urskov In the real world, the CNS and OTU are not all that important to track to the last decimal point... They are highly inacurate. When looking at my PO2, I rarely have above 1,3 during the bottom portion of the dive. It tends to be 1,2 - 1,3. So the average value of 1,25 is closer to what you are actually doing. But even when doing deep'ish and long dives, the few minutes extra in deco time won't make the difference between perfectly fine - or a serious bend. It's a contributing factor, but 4-5 minutes out of 60-90 minutes obligations amounts to very little. __________________ www.johnnychristensen.com Wreckphotography from the cold north
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