Patent ID: 8410948

Claim:
A single-terminal moving wastewater holding tank sensor probe for use in determining presence of conductive liquid within a wastewater holding tank, the single-terminal moving wastewater holding tank sensor probe comprising: an electrical terminal configured for wiring into a level measuring circuit, wherein: an electrical connection to the electrical terminal is configured to pass a time-invariant electrical signal with a constant voltage applied during normal operation while determining presence of conductive liquid within the wastewater holding tank, and the electrical terminal is configured for electrical connection to other probes during normal operation that collectively measure a level of the conductive liquid in the wastewater holding tank; an electrical contact configured for wiring into a level measuring circuit; a probe tip configured for contact with fluid within the wastewater holding tank during normal operation; an electrical conductor for electrically coupling the electrical terminal and the probe tip, whereby the electrical conductor is configured for installation through an aperture in the wastewater holding tank during normal operation, and wherein only one conductive element passes through the aperture; an electrical insulator at least partially encapsulating the electrical conductor, wherein: the electrical insulator comprises a non-conductive material having an exposed surface that is configured to be in contact with any fluid in the wastewater holding tank in the region between the aperture and the probe tip, wherein: the non-conductive material comprises a tubular portion aligned with an axis of the electrical conductor, and the tubular portion has a circular geometry with an outside diameter of less than a quarter inch, and a path from the probe tip and along the exposed surface toward the aperture, during normal operation, wherein the path comprises a length-to-width ratio that exceeds 2.0, and wherein the length to-width ratio is a length of a conductive residue path on the exposed surface in a direction substantially parallel with the electrical conductor divided by the width of the conductive residue path on the exposed surface in a direction perpendicular to the length; and a fitting suitable for sealing the aperture, wherein the fitting is annularly configured around at least one of the electrical terminal and the electrical conductor.