Megger mit5001000 insulation testers megger 1001 945 the megger mit1025 dc insulation tester offers preconfigured diagnostic tests including insulation resistance ir polarization index pi dielectric absorption ratio dar dielectric discharge dd step voltage sv and ramp test ease and speed of use are key points of this instrument it runs from from rapid charge batteries a 30min charge will give gt60mins run time alternatively it will run from a mains supply it has a large