is valid for the
failure rate in fit
(10-9/h).
The expected value is determined for each
component on the basis of long term tests and field
experience. Long term tests refer to a minimum test period of
t > 10000 h.
If such a test is carried out at a temperature of 85°C, for
example, that would, in an appliance with a surrounding
temperature of T < 40°C, correspond to an operating
time of 150000 - 200000 hours; a value which comes close to
real operating conditions. Due to the element of
uncertainty about accuracy of these calculations, a subject
which has also been described in technical literature, this
value is given with a confidence limit of 60%. However,
according to our experience, these values largely correspond
to the field results.
Correction factors which are specific to the different
applications, result from temperature and/or voltage stress
capacity according to the following tables. |