Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Gain access to burner

Measurement:

Inspect the two spark electrode for any signs of damage, cracks to the ceramic or build-up of debris.
Check the gap between the two electrode tips is approximately 4mm and the gap between the spark electrodes and the burner is approximately 10mm.
Carry out a resistance check between the tip of the
each spark electrode to its inline connector.
Resistance should be short circuit (zero resistance).