In article ,
"Dave Plowman (News)" writes:
About a couple of years ago I bought two of these in R80 23w form for a
couple of lamps that get fairly heavy use. The anglepoise on the
electronics workbench and the computer keyboard light. To save on running
costs and to allow easy movement of the anglepoise due to lower heat. They
were very expensive - IIRC something like 15 quid each. And one has failed
- not the workshop one that gets bashed a bit, but the computer one which
never gets touched. They're said to have a life of 10,000 hours. So even
at 4 hours a day - an over generous estimate - they should last about 7
years.
So much for cost saving CFLs...

Genuras are electrodeless induction fluorescents.
Their life is pretty much the life of the electronic control gear.
The life of electronic components is governed by random processes,
and it's not so much a case of wearing out, as a probability that
the lamp will have failed after so many hours. That means the life,
whilst long, has a much bigger standard deviation. The other one
could go on for 20,000 hours. The biggest effect on life of such
components is temperature -- roughly, the expected life halves
for each 10C temperature rise. Therefore using the Genura in a
well ventilated fitting is the most important factor for lamp
life. I've had some which did over 20,000 hours, but then you
start getting into the realm of the phosphor wearing out. I
recall one infant mortility too.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]