Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the ignition electrode from the burner door assembly

Measurement:

Measure the resistance across the ignition electrode.
Expect continuity / zero resistance.
Visually inspect the condition of the electrode, it should be clean undamaged and free from distortion (see image).
Also check the spark gap which should be approximately 2mm as shown
Are the electrode checks satisfactory?