Martindale et4000 et4500 and et4500 pro multifunction testers martindale et4000 the et4000 tester from martindale can carry out all the tests needed to verify the safety of electrical installations in domestic commercial and industrial wiring installations inaccordance with amendment 3 to thebs7671 17th edition wiring regulationson connection the tester carries out an automatic polarity and wiring check identifying potentially dangerous wiring faults in advance of any testing fast reli