MAGNETIC-FLUX AND LOSS MEASUREMENTS USING THIN-FILM SENSORS

Traditionally the magnetic field distribution throughout electrical ma chine core is obtained by positioning miniature enamelled copper wire search coils on test laminations stacked in an experimental core. Howe ver their physical presence, when inserted in a core, changes the flux and field distribution, creates localised stress and also an air gap between two adjacent laminations, To overcome this drawback, sensors c omprising a thin film structure have been deposited on the surface of several laminations by vacuum evaporation of metals, Differences betwe en the results obtained using conventional and thin film search coils are within the limits of experimental errors.