Patents Assigned to Southwest Pump Company
  • Patent number: 4591946
    Abstract: An elongated capacitance probe for use in a measuring system for locating a liquid level interface in a tank is provided. The probe includes an outer casing having first and second substantially semi-circular matingly engaging portions, the outer casing having top and bottom ends defining a length thereof approximately equal to a height of the tank. Spacers are mounted in opposed relation in the outer casing to form spacer pairs, the spacer pairs located in a spaced apart relationship along a longitudinal axis of the outer casing. A plurality of ground plates are mounted in a spaced apart relationship in the spacer pairs. To locate the liquid level interface in the tank, one or more capacitor plates are mounted in the spacer pairs, each capacitor plate mounted between a pair of ground plates, and extending substantially the length of the outer casing. Each of the capacitor plates in combination with a ground plate forms a capacitor extending substantially the entire length of the outer casing.
    Type: Grant
    Filed: April 30, 1985
    Date of Patent: May 27, 1986
    Assignee: Southwest Pump Company
    Inventor: Woodrow W. Pope
  • Patent number: 4589077
    Abstract: A liquid level height within a tank is measured by means of an elongated multi-segment capacitance probe that includes a column of capacitors extending through a liquid level interface. Each capacitor of the probe is sequentially measured in response to microprocessor controlled instructions as part of a measuring unit located at the tank. Up to sixteen measuring units may be interconnected in a field and individually connected to a microcomputer system at a central station. The microcomputer system addresses each of the measuring units and sends a select signal to the microprocessor controller of the measuring unit to sequentially measure each capacitor of the probe. By identifying the capacitor at the liquid level interface, the height of liquid within a tank is computed by the microcomputer system. From this height measurement and stored tank data, the volume of liquid within a tank is calculated.
    Type: Grant
    Filed: July 27, 1983
    Date of Patent: May 13, 1986
    Assignee: Southwest Pump Company
    Inventor: Woodrow W. Pope