Megger tdr500 3 cable tester megger 1002 227 p the megger tdr500 3 cable tester uses time domain reflectometry to locate faults on metallic cables it has a minimum resolution of 0 1 m and a 5 km maximum range depending on velocity factor selected and cable type with four output impedances 25 50 75 and 100 omega and a velocity factor from 0 2 to 0 99 it meets any cable test requirement the tdr500 3 is a hand held compact instrument which is simple and intuitive to use p p the au