CCR Fatality (Feb 2013) - Australian Inquest Output

[emmbee]

That what it says. One of the cells could reach 1.3, the other couldn't.

 

[rjack]

Many thanks for your explanation, so both cells that were current limited during the dive were off a similar age - 40 months but had different current limitations.

Not sure what you mean by "different" current limitations. Current limited means they have non-linear output. As the loop ppO2 went up their mV output did not.

In this case the 2 current limited cells were roughly similar in output (below actual) and the voting logic relied on them and outvoted the cell which was closer to the true ppO2.

 

[Andy Del]

Andy if I am understanding you correctly you are saying that if he did a dil flush the 2 bad cells would read lower than the PO2 of his dil at that depth?
This is not necessarily true and more likely if the unit was not calibrated correctly. The more likely scenario during a dil flush of current limited cells is that they would all read an accurate PO2 at lower PO2s (during a dil flush). If they all read correctly during a dil flush this tells you that the cell reading a high PO2 COULD be the correct one and the loop is not safe at the higher PO2 levels because you do not have a verified accurate means of monitoring it.


Sent from my iPhone using Tapatalk

Either way Michael, your comments are quite likely as well. However, as it was presented by Paul at Oztek 2 years ago, the cells would produce less current in the same gas over time as they 'tired', so getting a lower than expected reading is quite possible as well. I know with the oldest cell on my JJ a few weeks ago I got a lower than expected reading post dive when the loop was returned to normal air... s in 0.17...

Or my take on that is BS... either way, a dil flush would have been a clue that something was not right.

cheers

Andy

 

[Mr fish]

Diver would prob need to switch to low sp then push up the ppo2 till he could see the two carp cell,s stop , and the good one move up
But dill full would have been on the cards first for me, get back to a known ppo2,

It's ok us all washing are hands of it cos he had v old cell,s but could happen to us all even with newer cell,s in are units ,

Something to think about ,

 

[mick4707]

And don't forget that Fil had the extra task loading of 2 students, both very competent divers but still would have required Fils attention

 

[Mark Chase]

And don't forget that Fil had the extra task loading of 2 students, both very competent divers but still would have required Fils attention

Which is a key point


All but the most self obsessed will know that when we do a trainig or observed dive we are much more likley to screw up than when we are on a normal dive. The peer presure and instructor presure causes brain farts.

It is neive to think just because someone has an instructor badge they dont suffer the same presure.

I have argued in the past that when solo diving my attention is 100% on me and when buddy diveing with experianced buddies its more like 60/40

I know when i am diveing with my wife or kids its more like 80% on her and 20% on me

Probably the same if i were teaching

ATB

Mark

 

[M@lly]

I***8217;m a ***8220;new***8221; user and sorry for my English.

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Cells: 2 at 1,27 and 1 at 1,7.

Dil. F.: PpO2 is in a safe range and I ***8220;know***8221; what I breathe or at lower PpO2 all the cells agee.

Check mV, the highest is the one at 1,7, strange but I know the other 2 cells have 40 month....

Manually set the SP at 1, that could be 0,6 or at lower PpO2 all the cells are agree.

At a depht where it is possible, i.e. 22 m, dil.f. with 50/20, 1 at 1,6, other 2 at 1,2....

Now manually set the SP, not ***8220;high***8221;, I need more deco, stay more in the water, that is the reason I bought a reb. Or SCR, or BO.

At home I can do everything I wont.

*

I quote Mark, sure it is too much when teaching......