The magnetic shunt properties of a kind of M.S.O. Alloy (31%Ni, 8.5%Cr and rest Fe) containing C from 0.019 to 0.150% were studied. The magnetization curves at 0°to 40℃ were measured by the ballistic method. The dimension of specimen was 0.4 cm in diameter, 3.1 cm in length, and so the demagnetization factor N was 0.30. The experimental results on magnetic shunt properties are summarised as follows : (1) With increasing C addition, the permeability decreases at first and then increases slightly through a feeble minimum. It is assumed that the former decreasing is due to the impurity of C and the latter increasing due to the formation of Fe_6Cr_C_6 which is speculated by the microscopic. texture and the calculation. (2) The temperature coefficient of permeability becomes larger with increasing C addition, and its linearity becomes worse
