MPI-530-IT meter is a multi-functional instrument for electric shock protection measurements including the option of various methods for measuring earthing and earthing resistance. Sonel MPI-530-IT allows testing of residual current devices (RCD), types AC, A, F and B also in IT network. Additionally the meter enables its user to analyse power supply parameters, records and displays them on its screen. The instrument automatically measures the insulation resistance in a socket and in 3 -, 4 - and 5-wire cables when used with AutoISO-1000C adapter. Measurement results may be continuously verified, depending on user’s demand or according to binding regulations. Memory of the instrument may store tens of thousands of measurements allowing users to store them in a structure of a protocol and describe individual measurement points.