Assuming you mean "test" an element. IR test between Earth and Line, IR test between Earth and Neutral at 250V. I would suggest that if all appears OK that you then put the appliance on (heat up to, say around 250DegC) then unplug/disconnect and test again with elements hot.
Also worth checking out the cooker hood controls, if it's one of the ones with a sliding carbon based slider switch for fan speed, they can cause problems when worn.
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