摘要 |
A tubular flexural bar (15), consisting of magnetic material, contains an iron core (23) of magnetically soft material, on opposing limbs of which are wound a pair of exciting coils (27,28). The shaped corners of the iron core (23) make good magnetic contact with the inner surface of the flexural bar (15). Magnetic flux is induced by the coil excitation in three parts, the first two producing flux which passes through two paths in the flexural bar, whilst a third flux circulates around the core and through the air gap (25) to be detected by a Hall element (26). When the flexual bar (15) is loaded, its reluctance changes and the first fluxes become unequal, changing the gap flux with a resulting signal from the element (26) being related to the distorting force applied to the flexural bar (15). |