Measurement of magnetic fields using a string fixed at both ends

摘要

A method and apparatus is disclosed for detecting magnetic fields in which a string (1) carries an alternating current. The displacement of the string from its unperturbated position due to a magnetic gradient across the string is detected by pick-up coils (L1, L2). The signals from the pick-up coils are demodulated using a signal derived from the alternating current to produce an output.