Inspiration and Evo 3 cell backup system.

divetheworld · 24th April 2008, 10:29

Quote: (Originally Posted by Brainx3)

Hi,

Thanks for the info Brent. However, again I say, I never mentioned anything regarding controllers. What this backup system is offering is a simple monitoring instrument with built-in deco software. I realize that it can be configured to monitor different cells, but my point is that since cells can fail (sometimes without any notice) then connecting the extra handset to the same cells won't be much of a good for the diver.

If my Vision electronics failed then the backup handset only can be used in this case to monitor the same primary cells and show deco information and I would still need to run the unit manually. If you want true redundancy to monitor PPO2 then I personally would install another 3 cells and connect the extra handset to them, because then if anything happened to my primary electronics or the primary cells then I have another set that I can rely on.

If you want true redundancy for controllers, then the extra handset should have extra feature to control the solenoid and that feature can be set from a passive to active when needed in order to have extra controller that would back up your electronics in case the primary electronics failed.

Best Regards. Wael

Wael,

All very good points, I'll try to address them as best as I can.
There is no controller function on the Pursuit computer, if we were to integrate a "truly" independant backup system then we would not be able to use the Vision's solenoid as this may be the cause of the fault. If there is a flag tied in to activate the secondary system in the event of a primary failure, like a hand-over from master to slave then it is also not truly independant.
It is feasible that a system could be designed that stays as a dormant monitor with deco and activates if the PO2 drops to a point where it can be assumed that the primary has failed but that would need extensive FMEA work carried out to ensure that it would reduce the risk effectively without creating further complications. Certainly if the old APD solenoid was in use on the primary then a "stuck open solenoid" failure would not be mitigated by this and manual control from the tank would be the logical course of action.
We charted the full list of possible failures, symptoms and corrective actions to come to the conclusion that taking into account state of the art, and technical and economic factors, that this is not practically acheivable at the moment as an aftermarket solution.
This leaves the fact that if a serious primary failure was to occur, then the best computer available to decide how and when to inject oxygen into the loop is the one between your ears. What the diver needs is adequate information to decide what to do. Using 4 cells accross two handsets does this.
Lastly, fitting six cells would be truly redundant but there is insufficient room inside an APD unit to do this well, five is about the maximum. We do five for the classic and can do for the Deep Pursuit upon request free of charge.
If you can fit six in your head, then our kit will allow you to monitor six.
Again, we have allowed the end user to decide to what extent he requires that redundancy to acheive.

Brent

Brainx3 · 24th April 2008, 12:08

Hi,

Thanks for the clarification. Eventually, any redundancy system is better than nothing.

Best Regards. Wael

dave t · 24th April 2008, 16:26

Just got back from doing a trimix course using the three sensor connection kit from narked@90 works perfectly.

absolutely superb,

thanks John and Brent

Dave

24th April 2008, 10:29	#71 (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: 1,557	Re: Inspiration and Evo 3 cell backup system. Quote: (Originally Posted by Brainx3) Hi, Thanks for the info Brent. However, again I say, I never mentioned anything regarding controllers. What this backup system is offering is a simple monitoring instrument with built-in deco software. I realize that it can be configured to monitor different cells, but my point is that since cells can fail (sometimes without any notice) then connecting the extra handset to the same cells won't be much of a good for the diver. If my Vision electronics failed then the backup handset only can be used in this case to monitor the same primary cells and show deco information and I would still need to run the unit manually. If you want true redundancy to monitor PPO2 then I personally would install another 3 cells and connect the extra handset to them, because then if anything happened to my primary electronics or the primary cells then I have another set that I can rely on. If you want true redundancy for controllers, then the extra handset should have extra feature to control the solenoid and that feature can be set from a passive to active when needed in order to have extra controller that would back up your electronics in case the primary electronics failed. Best Regards. Wael Wael, All very good points, I'll try to address them as best as I can. There is no controller function on the Pursuit computer, if we were to integrate a "truly" independant backup system then we would not be able to use the Vision's solenoid as this may be the cause of the fault. If there is a flag tied in to activate the secondary system in the event of a primary failure, like a hand-over from master to slave then it is also not truly independant. It is feasible that a system could be designed that stays as a dormant monitor with deco and activates if the PO2 drops to a point where it can be assumed that the primary has failed but that would need extensive FMEA work carried out to ensure that it would reduce the risk effectively without creating further complications. Certainly if the old APD solenoid was in use on the primary then a "stuck open solenoid" failure would not be mitigated by this and manual control from the tank would be the logical course of action. We charted the full list of possible failures, symptoms and corrective actions to come to the conclusion that taking into account state of the art, and technical and economic factors, that this is not practically acheivable at the moment as an aftermarket solution. This leaves the fact that if a serious primary failure was to occur, then the best computer available to decide how and when to inject oxygen into the loop is the one between your ears. What the diver needs is adequate information to decide what to do. Using 4 cells accross two handsets does this. Lastly, fitting six cells would be truly redundant but there is insufficient room inside an APD unit to do this well, five is about the maximum. We do five for the classic and can do for the Deep Pursuit upon request free of charge. If you can fit six in your head, then our kit will allow you to monitor six. Again, we have allowed the end user to decide to what extent he requires that redundancy to acheive. 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. 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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24th April 2008, 12:08	#72 (permalink)
Brainx3 Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Aug 2007 Location: Borås, Sweden Posts: 274	Re: Inspiration and Evo 3 cell backup system. Hi, Thanks for the clarification. Eventually, any redundancy system is better than nothing. Best Regards. Wael __________________ The depth of life cannot be measured in Bars, nor can the sea of lies, that lies within. *I don't take crap for an answer...*
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24th April 2008, 16:26	#73 (permalink)
dave t Custom Title Allowed! Current Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss Dolphin Ray Azimuth Home Build Other Rebreather/s: Dolphin Ray Azimuth Home Build Join Date: May 2005 Location: UK Posts: 654	Re: Inspiration and Evo 3 cell backup system. Just got back from doing a trimix course using the three sensor connection kit from narked@90 works perfectly. absolutely superb, thanks John and Brent Dave
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