| 摘要 |
<p>A method for determining the value of a physical variable such as pressure, distance, volume or the like, comprises the following steps: a) Generating a magnetic flux density distribution (44.1, 44.2) in a volume (42) filled with a ferrofluid (43); b) changing the volume (42) responsive to the value of the physical variable; c) measuring the variation of the flux density distribution (44.1, 44.2) which is caused by the change of the volume (2) in order to determine the value of the physical variable. A differential pressure transducer according to the method uses a ferrofluid contained in two interconnecting chambers, enclosed by two non-magnetic spring diaphragms. At least one inductance circuit measures the variations in the volumes of ferrofluid in the interconnecting chambers. Changes in pressure displaces the non-magnetic spring diaphragms, causing the volume in each in the connecting chamber to change in a differential manner. <IMAGE> <IMAGE></p> |
