The instrument can perform a phase against phase, phase against neutral conductor and phase against protective conductor (PE) impedance measurement and an expected short-circuit current calculation (according to EN 60909-0). Since the instrument performs a 4-wire measurement, the measurement results are not affected by test lead resistance and alligator clips; and it is not necessary to calibrate the test leads.
The instrument is supplied with double-contact crocodile clips via special cables: the back and red part of the crocodile clips are electrically isolated and provide two different measuring points. The red sides of the alligator brackets represent the current circuits (C1 and C2) while the black sides (P1 and P2) represent the voltage circuits.
The IMP57 is supplied directly via the test leads and the electrical network under test. It is not equipped with a keyboard because all commands and results are exchanged with the MASTER instrument (Combi G2, Combi G3, Combi 420, Sirius, Genius, GSC53 or GSC60) via the RS232 serial interface.