Patent ID: 7938002

Claim:
An apparatus for detecting a level of electrically conductive fluid in a container below a non-conductive fluid layer, comprising: a handle with an electrically conductive threaded shaft extending from the handle on one end, along an axis of the handle; a housing with one portion of the housing perpendicular to the axis of the handle and containing an aperture through which the shaft extends, and another portion of housing transverse to the first portion, the housing having an electrically conductive surface in contact with and in electrical continuity with the threaded shaft; an electrically conductive yoke connected to the handle by the threaded shaft with the first portion of the housing sandwiched between the yoke and the handle, the yoke being in electrical continuity with the threaded shaft; an electrically conductive circular spool mounted to the yoke and capable of rotation relative to the yoke about an axis located in the center of the spool, the spool being in electrical continuity with the yoke; a lever extending from the spool, allowing the spool to be rotated relative to the yoke; a measuring tape formed from strip of metal and wrapped around the spool, with one end of the tape secured to and in electrical continuity with the spool, the tape defining a single conductive path, and a solid metal electrically conductive weight device attached to and in electrical continuity with the other end; a battery carried within the housing and electrically connected to the conductive surface of the housing; a ground wire connected to the battery and having a free end extending from the housing for connection to a grounding surface in electrical common with the conductive fluid, defining a current flow path from the battery to the conductive fluid; and an indicator that provides a signal when a current passes.