Gel wrote:
I have NFPA document [can't see on website]detailing sound logic for
the 10 year cycle.
Its down to the MTBF rating.
=== MTBF is NOT ten years. MTBF alone does NOT predict end of life for
equipment. It DOES predict the earliest time, on the left of a bell curve,
when a component IN the equiment might fail.
....

On CO ALarms most CO cells have max life of 6 to 7 years and many will
shut down via in built firmware.
=== I would like to see your source on that, or at least some reference to
a source. I dispute the numbers.

AGain research shows they do not operate within the UL or British
Standard parameters, ie start to drift & become less sensitive.
....
What research? What brands of CO alarms are you finding that do NOT employ
the UL/CSA/EC/ any safety rating? If you bought such a device in the UK or
in North America, you bought an illegal device which cannot be sold to you
legally. I would like to know where you found this information.

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