This part of ISO 6518 specifies the methods and test conditions for testing battery-supplied ignition sys-tems for spark-ignited internal combustion engines.
Because of the difficulties in producing repeatable measurements with atmospheric spark gaps and dif-ferent observers, two methods of obtaining the re-sults necessary for calculating the system output energy are given.
Method A —using spark gaps for the energy measurement (test arrangement A).
The output energy obtained by this method is called spark energy, Esp.
Method B —using a Zener diode string for the en-ergy measurement (test arrangement B).
The output energy obtained by this method is called Zener discharge energy, Ezd.
This method is not suitable for systems giving alter-nating spark current.
Method B is also recommended for the comparative testing of ignition coils and current interruption sys-tems.