What Is to be understood by “Proof Test”?
In a safety-relevant application the safety-relevant electrical control system
(SRECS) must be in a state that guarantees the specified safety integrated level
from the point of view of risks. The proof test is the test to be carried out to confirm
this in the end.
Errors or deterioration in a subsystem of the SRECS might be recognized during
the test. If this is the case, you must take measures for the subsystem to return the
SRECS to a state that is as close as possible to the “as new state”.
In any case the specified safety integrated level must be proven to be reestablished
and guaranteed. As long as this is not the case the proof test is not
concluded and the safety-relevant application is not be put back into operation.
The proof test interval is included as 1 T in the formula of the basic subsystem
architectures of IEC 62061 for calculating the dangerous failure rates.