NSG 438
5
A simulation device must be constructed such that it reproduces practical
conditions realistically. Furthermore, the results obtained (interference
sensitivity threshold) must be reproducible.
The interference immunity of an instrument is not only dependent on its
construction, it is also largely dependent on the quality or the consistency
of the mass production techniques used. Knowing this has led to the
demand for individual testing or at least random sample testing.
Further weak spots, which could affect the overall interference immunity,
can arise through the assembly of instruments into complete systems
because of the installation method used, the cabling and the earthing. An
ESD check on systems is therefore also prescribed. Such tests provide
valuable information about the immunity of the system to effects that occur
only sporadically under operating conditions and hence represent difficult
to detect sources of disruption.