| 摘要 |
A differential pressure transducer for measuring external pressures is disclosed. The pressure transducer uses a ferrofluid contained in two interconnecting chambers, enclosed by two non-magnetic spring diaphragms. In this embodiment, two independent inductance series circuits, each comprising a bar magnet, Hall effect sensor and an iron pole piece, measure variations in the volume of ferrofluid in each of the interconnecting chambers. Changes in pressure displace the non-magnetic spring diaphragms causing the volume in each interconnecting chamber to change in a differential manner. The flux path in the series magnetic circuit is distorted by changes in the volume of the ferrofluid, causing changes in the flux density at the sensing area of the Hall effect sensor, this sensor producing an electrical signal proportional to the flux change. The differential output of the two Hall Effect sensors contained in the two series magnetic circuits produce an electrical signal proportional to the applied differential pressure.
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