Max Cell Output voltage for VR3

SteveL · 4th March 2006, 02:36

Hello all,

I am looking to make a 4th cell holder for my 15.5. As you know the cells mainly used in this unit are the large R10 cells with an output of 20-23mV (in air at the surface)

So it would make sense to make a holder that suits these cells so there is no need to carry another type of cell that cant be used in the breather should one go down for some reason. Most of the 4th cell holders are made for the R22 style of sensor which out put about 10mV (in air at the surface)

The question is can I use the R10 in the VR3 with out damaging it.

Given that the voltage output is more or less linear then if you had pure 02 at 10m then the out put with an R22 is going to be about 20mV which I know the vr3 can handle - it will also take some higher voltages from this cell (but dont ask how I know that......)

So at face value the VR3 should handle the R10's 20 odd mV but what is the limit?? will it take upto 50mV ?? for arguments sake ....I can find anything on the delta P site regards the max but Im sure there is one..

Regards,

Steve L

***Beanie*** · 4th March 2006, 07:02

No idea but if itss 20mv at 10m in O2 then it would still be 20mv at 200m with a PPO2 of 2.0?
Is that right or am I barking up the wrong tree?

I'm guessing the biggest problem will be calibrating it.

**nigelh** · 4th March 2006, 07:09

Quote: (Originally Posted by SteveL)

Given that the voltage output is more or less linear then if you had pure 02 at 10m then the out put with an R22 is going to be about 20mV which I know the vr3 can handle - it will also take some higher voltages from this cell (but dont ask how I know that......)

So at face value the VR3 should handle the R10's 20 odd mV but what is the limit?? will it take upto 50mV ??

Your numbers are funny.

20mV in surface air implies 100mV in O2 at 1bar implies 200mV at 10m in pure O2

SteveL · 4th March 2006, 11:26

Nigel - yes you are right my numbers are crazy ramblings of a mad man sitting in an airport lounge at 3am and a 6 hour fight in front of me

The output of the R22 is about 10mV or so at the surface in air (PO2 .21) so at any depthe and PPO its hard to work out as the slope of the line may be a bit different for each cell, assuming the output is linear which it nearly is - I mistakedly did the numbers - double the PO2 therefor double the mV which is not correct as you say....... shouldnt have starded a technical rambling so late at night and Pissed off for the delayed flights......

Anyway question still remains how many mV can the VR3 handle and can I plug an R10 into it??

Mdemon · 5th March 2006, 08:09

Might be worth banging an email off to DeltaP? They can be very helpful...

4th March 2006, 02:36	#1 (permalink)
SteveL Custom Title Allowed! Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Join Date: Nov 2005 Location: Sydney Australia Posts: 222	Max Cell Output voltage for VR3 Hello all, I am looking to make a 4th cell holder for my 15.5. As you know the cells mainly used in this unit are the large R10 cells with an output of 20-23mV (in air at the surface) So it would make sense to make a holder that suits these cells so there is no need to carry another type of cell that cant be used in the breather should one go down for some reason. Most of the 4th cell holders are made for the R22 style of sensor which out put about 10mV (in air at the surface) The question is can I use the R10 in the VR3 with out damaging it. Given that the voltage output is more or less linear then if you had pure 02 at 10m then the out put with an R22 is going to be about 20mV which I know the vr3 can handle - it will also take some higher voltages from this cell (but dont ask how I know that......) So at face value the VR3 should handle the R10's 20 odd mV but what is the limit?? will it take upto 50mV ?? for arguments sake ....I can find anything on the delta P site regards the max but Im sure there is one.. Regards, Steve L
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4th March 2006, 07:02	#2 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,174	Re: Max Cell Output voltage for VR3 No idea but if itss 20mv at 10m in O2 then it would still be 20mv at 200m with a PPO2 of 2.0? Is that right or am I barking up the wrong tree? I'm guessing the biggest problem will be calibrating it. __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
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4th March 2006, 07:09	#3 (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: 838	Re: Max Cell Output voltage for VR3 Quote: (Originally Posted by SteveL) Given that the voltage output is more or less linear then if you had pure 02 at 10m then the out put with an R22 is going to be about 20mV which I know the vr3 can handle - it will also take some higher voltages from this cell (but dont ask how I know that......) So at face value the VR3 should handle the R10's 20 odd mV but what is the limit?? will it take upto 50mV ?? Your numbers are funny. 20mV in surface air implies 100mV in O2 at 1bar implies 200mV at 10m in pure O2 __________________ nigelh
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4th March 2006, 11:26	#4 (permalink)
SteveL Custom Title Allowed! Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Join Date: Nov 2005 Location: Sydney Australia Posts: 222	Re: Max Cell Output voltage for VR3 Nigel - yes you are right my numbers are crazy ramblings of a mad man sitting in an airport lounge at 3am and a 6 hour fight in front of me The output of the R22 is about 10mV or so at the surface in air (PO2 .21) so at any depthe and PPO its hard to work out as the slope of the line may be a bit different for each cell, assuming the output is linear which it nearly is - I mistakedly did the numbers - double the PO2 therefor double the mV which is not correct as you say....... shouldnt have starded a technical rambling so late at night and Pissed off for the delayed flights...... Anyway question still remains how many mV can the VR3 handle and can I plug an R10 into it??
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5th March 2006, 08:09	#5 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,927	Re: Max Cell Output voltage for VR3 Might be worth banging an email off to DeltaP? They can be very helpful... __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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