Abstract: A liquid level measurement capacitance probe is disclosed comprising an elongated outer capacitor tube, an elongated inner tube coaxially mounted within the outer capacitor tube to form a capacitor annulus therebetween with the inner tube having a plurality of longitudinally extending capacitor elements cooperating with the outer capacitor tube to form a plurality of individual capacitor units, a connector unit for electrically connecting the capacitor units to an electronic circuit processor for measuring capacitance values of the capacitor units in calculating a fluid level, a filter for separating water from fuel flowing from the storage tank to be measured to the capacitor annulus, the filter having an annular housing mounted about the outer capacitor tube with an inlet port adapted for fluid communication with the storage tank, an outlet port connected to the capacitor annulus between the inner and outer capacitor tube for delivery of filtered fuel to the annulus, a water discharge outlet for discharging

Abstract: A liquid level measuring device has an outer capacitance tube, an imperforate glass tube coaxially within the outer tube defining a capacitor annulus between them, and an inner capacitor sleeve coaxially within the glass tube and having separate longitudinally extending sleeve sections. The separate sleeve sections cooperate with the outer capacitance tube to form a plurality of capacitor sections each having a separately measurable value which varies between dry minimum and submerged maximum.

Abstract: A liquid level measuring system for the underground fuel storage tanks of a fuel dispensing station having a multiple segment capacitance probe in each storage tank and a microcomputer for periodically measuring the capacitance of each segment of each probe and calculating the level and volume of fuel in each tank using capacitance and volume calibration constants automatically updated by the microcomputer from the measured capacitance data and from fuel delivery data automatically fed to the microcomputer.

Abstract: An electrical counting device with a rotary counter, a rotary drive assembly having a driven rotor with a verge for indexing the counter in stepwise fashion and a coaxial drive rotor in frictional engagement with the driven rotor, a coil torsion spring biasing the drive rotor in one angular direction and a tension wire conductor extending angularly about a drum of the drive rotor and connected to be heated and thereby lengthened with an electrical current to index the counter a first one-half count with the torsion spring and a remaining one-half count with the tension wire upon subsequent cooling and contraction thereof.

Abstract: A borehole sensor is presented including a three axis gimbal device for determining (1) a vertical plane, using the force of gravity as a reference, (2) a horizontal plane, using the force of gravity as a reference, and (3) the north direction, using the earth's magnetic field as a reference. A motor drive system drives parts of the mechanism to desired positions about the three axes, and error transducers determine the deviation from desired positions about the axes and provide feedback to the motor drive system to eliminate the error.

Abstract: A control system is presented for controlling the operation of a borehole sensor. The borehole sensor includes a three axis gimbal device for determining (1) a vertical plane, (2) a horizontal plane, and (3) the north direction. Upon receipt of an initiation signal, the control causes a motor drive associated with each gimbal to drive error transducers on each gimbal to desired "home" positions about the three axes and error transducers determine the deviation from desired positions about the axes and provide feedback to the motor drive system to eliminate error. A home signal is generated when each error transducer reaches its home position. When home signals are received from all error transducers, the control system then senses the sign and magnitude of the error output from each error transducer and operates the motor drive system to drive the gimbals in directions to reduce the error. When each error transducer reaches its null position, the control terminates operation of its associated motor drive.