An a. c. two-core transducer assembly using a-Fe//4//0Ni//4//0B//2//0 and Fe//8//1B//1//3//. //5Si//3//. //5C//2 ribbon to detect small displacement is constructed. The amorphous material is kept at 'zero-flux state' by applying an equal and opposite a. c. magnetic field. When this state is disturbed by an external magnetic field, an a. c. signal which is proportional to the external field, appears. The results for sensitivity and linearity with displacement of source disturbing the magnetic state is presented for two configurations of the transducer.