Quote: (Originally Posted by
AD_ward9)
The CE issue first: if the unit has any electronics in it, or electrical, then EN14143:2003 requires compliance with EN61508, and that requires SIL4, which means that collectively all the critical failure modes together must have with an incidence of less than 1 per billion hours. As there are only about 5000 rebreathers in active use by sports divers, then if there is one death per year from this cause alone, then the system does meet any Safety Integrity Level required by Table 3 of EN61508-Part 2, and 10,000 times worse than the SIL-4 level required.
On the battery issue, you are absolutely correct. Dead battery should not mean dead diver.
Alex
There are a lot of dumb regulations Alex.
I know you keep banging on this, but there is IMHO a huge difference between a unit that has a battery that bounces and leaves the unit OFF (a serious fault) and one that has a SWITCH that can be TURNED OFF (which technically doesn't meet SIL4 yet IMHO is safer than one that has wet switches!)
Dead power in an ECCR is a serious matter. Even in an mCCR its serious if your PO2 monitoring no longer works.
Attempting to protect people against their own complacency isn't IMHO all that productive. We'd do better if we focused on identifying "surprises" in the way things work (defined: "surprise" = "not documented oh $hits that can kill you.")