1
Lawrence C Maier: Digital liquid-level gauging systems. Simmonds Precision Products, Edwin E Greigg, April 11, 1978: US04083248 (28 worldwide citation)

A liquid-level gauging system comprises a capacitive probe arranged in a liquid storage tank and electrically connected into timing circuitry of a pulse generator to render the period of the pulse output produced by the generator directly proportional to the probe capacitance and thus proportional t ...


2
Lawrence C Maier: Apparatus and method for determining liquid levels. Simmonds Precision Products, Dale R Lovercheck, March 13, 1990: US04908783 (22 worldwide citation)

A liquid level sensor system well suited for sensing the level of fuel in aircraft fuel tanks includes a plurality of capacitive sensors which provide an output capacitance that is a function of the fraction of the sensor wetted by the fuel. A plurality of sensors are positioned in the liquid-contai ...


3
Lawrence C Maier: Apparatus for the ratiometric measurement of a quantity of liquid in a tank. Simmonds Precision Products, Cushman Darby & Cushman, June 20, 1989: US04841227 (22 worldwide citation)

Apparatus for the ratiometric measurement of a quantity of liquid in a tank includes first and second capacitors disposed in a tank and responsive to an AC excitation signal. The output signal from the first capacitor corresponds to the quantity of liquid in a tank, while the output signal of the se ...


4
Lawrence C Maier: Capacitive measurement system. Simmonds Precision Products, Edwin E Greigg, January 17, 1984: US04426616 (22 worldwide citation)

A system for independently determining the capacitance and resistance of a capacitive sensor, in which the sensor and a reference capacitor are sequentially energized from two alternating voltage sources of different frequencies, and average sensor and reference capacitor current valves at the two f ...


5
Lawrence C Maier: Capacitive proximity sensors. Simmonds Precision Products, Edwin E Greigg, October 31, 1978: US04122708 (18 worldwide citation)

A capacitive proximity sensor for use in hostile environments comprises a ceramic substrate, and two conductive regions formed on the substrate and having opposed edges defining a narrow gap therebetween. The gap configuration is such as to maximize the fringing of electric flux lines outwards from ...


6
Lawrence C Maier: Capacitive type fuel probe compensation circuit. Simmonds Precision Products, Edwin E Greigg, July 29, 1980: US04214479 (14 worldwide citation)

A full height compensation circuit for a capacitive type probe of the type used to measure the mass of fuel in a tank which includes a probe capacitor for immersion in the fuel connected to a source of power for supplying current to the probe capacitor, the probe capacitor current being summed with ...


7
Lawrence C Maier: Apparatus and method for determining resistance and capacitance values. Simmonds Precision Products, Dale R Lovercheck, November 6, 1990: US04968946 (12 worldwide citation)

Apparatus and method for determining capacitive and resistive values of an electrical component, such as a fuel level determining probe, includes a waveform generator for subjecting the probe to a time-varying waveform that includes a linearly varying ramp portion and a fixed, constant portion. A se ...


8
Lawrence C Maier: Segment failure detector for digital display. Simmonds Precision Products, Edwin E Greigg, October 27, 1981: US04297692 (10 worldwide citation)

A circuit for detecting failure of a segment in a digital display which includes a comparator connected to the energizing circuit for the display segments so that when a segment fails and is addressed, the comparator output is changed to provide a blanking signal which is fed by a circuit to the bla ...


9
Lawrence C Maier: Method and apparatus for determining a quantity of liquid in a tank when at least one sensor is inoperative. Simmonds Precision Products, Dale R Lovercheck, June 23, 1992: US05124933 (9 worldwide citation)

A method and apparatus determines a quantity of liquid in a tank when at least one liquid sensor is inoperative. In a first embodiment, a plurality of tables are stored in memory which are grouped by identities of the possible inoperative sensor or sensors. One group of tables is selected based on t ...


10
Lawrence C Maier: Vibrating spool densitometer immune to cabling effects. Simmonds Precision Products, Cushman Darby & Cushman, February 7, 1989: US04802360 (6 worldwide citation)

Apparatus for use with a densitometer having a probe with an output and a probe driver for driving the probe includes a loop circuit coupled between the probe output and the probe driver. An amplifying circuit is coupled in the loop circuit to amplify the signal provided by the probe. A phase/gain c ...