Quote: (Originally Posted by
Gibbon)
I saw this happen to one of my cells, all was well then one cell crept up and up, I did a dil flush to confirm.
The cell read higher and higher, I cant remember exactly where it got to but it was translated to over 2.0pp when I was on 1.1.
After 10 mins the cell was 100% dead.
Yes it was a teledyne.
The failure mode you describe was almost certainly a leaking cell. If you let the electrolyte leak from an O2 cell, the output increases, then when enough has leaked, it dies.
I understand Teradyne have introduced some changes at the back end of last year to reduce the risk of electrolyte leakage.
When replacing the cell, use gloves and goggles as the electrolyte is extremely caustic.
All cells have this "feature" when the electrolyte leaks. If the electronics has a sensor load check capability, then this failure can be detected by the electronics because the load characteristics change: details of a circuit that does this is in the Compliance data and FMECA Vol 3, on our web site. We have not patented it, deliberately, so anyone can use this safety feature in their rebreather controller or PPO2 controller. It is possible to have all cells leak at the same time if you decompress them nastily, put differential pressures on them, or put your Rebreather at the back end of a RIB.
Quote: (Originally Posted by
Gilles)
Thanks for the excellent feedback.
Would you have more info about where to acquire the above mentioned AII cells? I think I want some.
Do you know if the Meg has a problem calibrating with a 4-25 mV range. I don't think so but I'm unsure.
The PSR-11-39-MD is a plug replacement for the Teledyne R22D (and R22-2BUD). Others in the range offer high output etc, so you should have an exact match.
Alex
Alex