Under normal circumstances, the instrument has infinite resistance. At this time, if the meter pointer is less than 0.5 megohm, the phase corresponds or the cable is confirmed!
Is to use megohmmeter to measure resistance and insulation test, the same cable must be conductive (the resistance is very small, 0 to 0.5 megohm), and different cables must be insulated (that is, the resistance is infinite or greater than 0.5 megohm)!