Patent ID: 7814788
Filing Date: 2010-10-19
Classification: G01F

Abstract:
1. An apparatus for determining the level of a liquid in a container, said apparatus comprising: (a) an electrically conductive support; (b) an electrically conductive platform supported by said electrically conductive support, said electrically conductive platform positioned above the level of the electrically conductive support, said electrically conductive platform for supporting at least one container for containing a liquid, said electrically conductive platform having an area less than that of the electrically conductive support; (c) an electrically conductive element, the distance between the electrically conductive platform and the electrically conductive element capable of being reduced or increased by relative movement between the electrically conductive element and the electrically conductive platform, said electrically conductive element overlapping said electrically conductive platform, wherein an RF capacitance measurement circuit connects the electrically conductive element to the electrically conductive support, wherein an electrical field is generated between the electrically conductive element and the electrically conductive platform; and (d) a capacitance sensor coupled to the electrically conductive element and arranged to provide an electrical signal representing the capacitance.