Patent ID: 9074922
Filing Date: 2015-07-07
Classification: G01F,G01R

Abstract:
1. A system for measuring a water level, comprising: a probe including a conductive rod and insulating spacers within a conductive tube, the conductive rod arranged coaxially within the conductive tube, the conductive rod extending through the insulating spacers, the conductive tube including perforations exposing the conductive rod and the insulating spacers within; a head connector connected to the probe; a coaxial cable connected to the head connector, the coaxial cable including an inner conducting wire within an outer conducting shield and separated by an inner insulator, the inner conducting wire and the outer conducting shield of the coaxial cable being in electrical communication with the conductive rod and the conductive tube of the probe, respectively, via the head connector; a pulsing unit connected to the coaxial cable, the pulsing unit configured to transmit a narrow pulse to the probe and to receive a positive first reflected pulse and a negative second reflected pulse therefrom via the coaxial cable, the positive first reflected pulse being from a head connector/air interface, the negative second reflected pulse being from an air/water interface of the water level, the pulsing unit configured to calculate a time between the positive first reflected pulse and the negative second reflected pulse and to convert the time to a distance that is indicative of the water level; and a calibration cable connecting the head connector to the coaxial cable, the calibration cable having an impedance that is higher than the coaxial cable but equal to that of the head connector, the calibration cable having a length less than that of the probe.