For Temperature Variations Patents (Class 324/670)
  • Patent number: 11340209
    Abstract: Sensor accuracy issues may arise when a humidity sensor is kept in a high humidity environment for an extended period of time. In these circumstances, a humidity sensor reading may tend to may become less accurate over time. To improve the accuracy of sensor readings, methods and systems described herein estimate and correct for sensor drift in high humidity conditions. Methods and systems described herein may use memory to store past humidity or other sensor readings so that an estimated amount of sensor drift may be determined to improve the accuracy of sensor readings. A memory may be embedded in a sensor module so that past readings for a given sensor module are stored in the memory of the sensor module. Algorithms for sensor drift compensation, and systems and methods that use such algorithms to improve the accuracy of sensor readings, are disclosed herein.
    Type: Grant
    Filed: March 19, 2020
    Date of Patent: May 24, 2022
    Assignee: Wagner Electronic Products, Inc.
    Inventors: Edward D. Wagner, Timothy Duncan, Anis Messaoud
  • Patent number: 11014571
    Abstract: A physical quantity measurement device includes a sensor element in which coupling capacitances are formed between a drive electrode and a first detection electrode and between the drive electrode and a second detection electrode; and a circuit device that includes a drive circuit which supplies a drive signal to the drive electrode, a detection circuit which detects physical quantity information corresponding to a physical quantity based on first and second detection signals from the first and second detection electrodes, and a failure diagnosis circuit. The circuit device includes first and second switches that are provided between first and second terminals to which the first and second detection signals are input and the detection circuit. The failure diagnosis circuit performs a failure diagnosis, based on a detection result of the detection circuit when connection states of the first and second switches are changed.
    Type: Grant
    Filed: October 30, 2018
    Date of Patent: May 25, 2021
    Inventors: Noriyuki Murashima, Teppei Higuchi
  • Patent number: 10440470
    Abstract: Disclosed is an electronic device including a housing; a speaker configured to output a sound signal; an enclosure surrounding the speaker and including a pipe passage, through which the sound signal moves in a direction facing an opening formed in the housing; a heat emitting structure mounted on an inner surface or an outer surface of the enclosure; a sealing member attached to the pipe passage; and a processor physically or electrically connected to the heat emitting structure and configured to control emission of heat.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: October 8, 2019
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Soo Hyun Park, Joo Hyun Kim, Doo Sun Yoon, Seung Bum Choi, Min Woo Yoo, Jong Chul Choi
  • Patent number: 10191006
    Abstract: A humidity sensor includes an insulating film formed on a semiconductor substrate, and a plurality of first electrodes and a plurality of second electrodes arranged on the insulating film so that each first electrode is adjacent to four of the second electrodes in four directions of up, down, right, and left when viewed in plan view, while each second electrode is adjacent to four of the first electrodes in four directions of up, down, right, and left when viewed in plan view. Metal wiring embedded in the insulating film electrically connects one of the first electrodes to another of the first electrodes, and electrically connects one of the second electrodes to another of the second electrodes. The humidity sensor has increased capacitance per unit area and improved adhesiveness and can be made using normal semiconductor manufacturing processes.
    Type: Grant
    Filed: February 23, 2016
    Date of Patent: January 29, 2019
    Assignee: ABLIC INC.
    Inventor: Toshiro Futatsugi
  • Patent number: 10018036
    Abstract: A system includes an optical fiber and an interrogator to provide source light to the optical fiber. The system also includes a receiver coupled to the optical fiber. The receiver includes at least one fiber optic coupler that receives backscattered light and that produces optical interferometry signals from the backscattered light. The receiver also includes photo-detectors that produce an electrical signal for each of said optical interferometry signals. The system also includes at least one digitizer that digitizes the electrical signals. The system also includes at least one processing unit that calculates I/Q data from the digitized electrical signals, corrects the I/Q data based on ellipse fitting, determines phase values based on the corrected I/Q data, and determines distributed sensing parameter values based on the phase values.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: July 10, 2018
    Assignee: HALLIBURTON ENERGY SERVICES, INC.
    Inventors: Andreas Ellmauthaler, Leonardo de Oliveira Nunes, David Andrew Barfoot, Christopher Stokely
  • Patent number: 9188609
    Abstract: It's disclosed a current monitor and an electric power quality compensation system. The current monitor includes: an internal monitor module configured to output a measurement of current for characterizing a real-time electric power quality of an external power network based on a received detection current, wherein an external detection module is used to detect a current of the external power network and output a first level detection current; and an isolation and transfer module including an input side and an output side electrically isolated from each other, wherein the input side is configured to be connected with the external detection module, and the output side is configured to be connected with the internal monitor module, the isolation and transfer module receives the first level detection current and outputs a second level detection current to the internal monitor module.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: November 17, 2015
    Inventors: Shaohua Chen, Yaping Yang, Bin Wang
  • Patent number: 8674709
    Abstract: A circuit for measuring a capacitance value of a touch screen includes: a target capacitor unit having a target capacitor charged with a target charging voltage; a target voltage control unit to charge the target capacitor; a reference capacitor unit having a reference capacitor charged with a charging reference voltage; a reference voltage control unit to charge the reference capacitor; a comparator to compare the target charging voltage and the charging reference voltage and output a transition signal at a moment when the target charging voltage becomes higher than the charging reference voltage; and a controller to receive an output signal of the comparator and a clock signal and generate a digital output signal and a control signal, wherein a capacitance value of the target capacitor is measured using a time elapsed from a time when the target capacitor is initialized to a time when the transition signal is outputted.
    Type: Grant
    Filed: May 12, 2011
    Date of Patent: March 18, 2014
    Assignee: Silicon Works Co., Ltd.
    Inventors: Ji Hun Kim, Hyun Min Song, Joon Ho Na, Ki Uk Gwak, Sang Gug Lee
  • Patent number: 8676550
    Abstract: A system and method are described that model a passive multiplexer, which may be used for a junction of a plurality of signal filters (e.g., radio frequency, microwave, satellite, etc.). Illustratively, based on obtaining parameters for the individual signal filters, an initial resonant frequency offset vector estimation may be calculated and input into a convergence algorithm to determine a set of multiplexer parameters. In particular, the convergence algorithm is generally different from the initial resonant frequency offset vector estimation calculation, and the initial resonant frequency offset vector estimation assists in achieving better (e.g., faster, more frequent) convergence on a set of multiplexer parameters from the convergence algorithm.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: March 18, 2014
    Assignee: The MathWorks, Inc.
    Inventor: Timothy Reeves
  • Patent number: 8593162
    Abstract: An object of the invention is to provide a fuel-aspect sensor having higher detection accuracy. A first electrode is inserted into a hole formed in a first housing member. A cylindrical second electrode is inserted into and firmly fixed to the first electrode by a cylindrical insulating member. A first elastic member, for example, made of rubber, is arranged between the first electrode and a second housing member. The first electrode has a large-diameter portion, which is biased by the first elastic member toward a sealing surface formed on an inner wall of the hole, so as to fluid-tightly seal a space between the first electrode and the second housing member.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: November 26, 2013
    Assignee: Denso Corporation
    Inventors: Hiroshi Nakamura, Akikazu Uchida
  • Patent number: 8542024
    Abstract: Methods and sensors for selective fluid sensing are provided. A sensor includes a resonant inductor-capacitor-resistor (LCR) circuit and a sensing material disposed over a sensing region. The sensing region comprises at least a portion of the LCR circuit. Temperature-dependent response coefficients of inductance L, capacitance C, and resistance R properties of the LCR circuit and the sensing material are at least approximately 5 percent different from one another. The difference in the temperature-dependent response coefficients of the properties of the LCR circuit and the sensing material enables the sensor to selectively detect analyte fluids from an analyzed fluid mixture substantially independent of temperature.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: September 24, 2013
    Assignee: General Electric Company
    Inventors: Radislav Alexandrovich Potyrailo, Cheryl Margaret Surman
  • Patent number: 8489341
    Abstract: A method and apparatus for monitoring fluid in a fluid line are disclosed. The apparatus includes a first capacitor and a processor in communication with the first capacitor. The first capacitor is configured to sense the capacitance of the fluid line at the first capacitor. The processor is configured to compare the sensed capacitance at the first capacitor with a reference capacitance to determine the composition of the fluid in the fluid line at the first capacitor. In some embodiments, the apparatus also includes a second capacitor. The second capacitor is configured to sense the capacitance of the fluid line at the second capacitor. The processor is configured to compare the sensed capacitance at the second capacitor with a reference capacitance to determine the composition of the fluid in the fluid line at the second capacitor.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: July 16, 2013
    Assignee: CareFusion 303, Inc.
    Inventor: Houston Brown
  • Patent number: 8410796
    Abstract: A method for calibrating apparatuses for determining the moisture content of products based on capacitive measurements comprises the following operating steps: Inserting a device (1) for simulating the dielectric properties of products in a measuring area of an apparatus (2) to be calibrated; taking a capacitive measurement with the apparatus (2) while the device (1) is inserted in the measuring area; modifying the device (1) settings at least once and taking the capacitive measurement again, for each different setting value; comparing each capacitive measurement taken this way with a corresponding known reference capacitive measurement; calibrating the apparatus (2) based on this comparison.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: April 2, 2013
    Assignee: Microtec S.R.L.
    Inventors: Marco Boschetti, Andrea Gottardo
  • Patent number: 8237454
    Abstract: Measuring device for local measurement of an electrical property of the content of a container, wherein at least three electrodes are disposed adjacently of each other in height direction and electrically insulated from each other, wherein each of the electrodes can be connected to an electrical measuring circuit for measuring, via one of the electrodes and one other electrode connected to an electrical earth, the electrical property of the content of the container in the vicinity of the electrodes, and wherein the electrical measuring circuit is adapted to generate at least one electric measuring signal representing the measured electrical property, and a control unit for connecting the one electrode to the electrical measuring circuit and connecting the other electrode to an electrical earth.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: August 7, 2012
    Assignee: Fluid Well Instruments B.V.
    Inventors: Marian Jozef Slezak, Cornelis Wijnand Schoenmakers
  • Publication number: 20090302870
    Abstract: A sensor and method for sensing moisture content of a medium such as soil is disclosed. In an embodiment, the sensor includes a sensing circuit, a processing module, a register, and a communications interface for communicatively coupling the sensor to an external communications device. In use, the sensing circuit generates a sensed signal having a signal parameter value attributable to the moisture content of the medium. The processing module processes the signal parameter value to provide, at an output, a scaled data value. The register stores a sensor identifier for the sensor and the communications interface is capable of communicating the scaled data value and the sensor identifier to the external device. An irrigation control system is also disclosed.
    Type: Application
    Filed: September 12, 2007
    Publication date: December 10, 2009
    Inventors: Neil D. Paterson, Richard J. Cave, Neil M. Wilson
  • Patent number: 7466147
    Abstract: A fluid quality sensor includes a first electrode (24) that has a fluid passageway (22) that is adapted to be placed in line with at least one fluid conduit (30). A second electrode (40) is supported within the fluid passageway (22) and electrically isolated from the first electrode (24). The first electrode (24) and the second electrode (40) operate as a capacitor for making fluid quality determinations. A disclosed example includes a temperature sensor (50) thermally coupled with a mounting member (42) that supports the second electrode (40) within the first electrode 24. A disclosed example includes a multiple piece first electrode that allows for at least a portion of the second electrode (40) to be exposed and accessible near one end of at least one piece of the first electrode during a selected portion of an example assembly process.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: December 16, 2008
    Assignee: Continental Automotive Systems US, Inc.
    Inventor: Daniel Stahlmann
  • Patent number: 7392444
    Abstract: The present method generates a greater number of hot holes than those generated by normal write/erase operations, thereby making it possible to evaluate an operation of a non-volatile memory with respect to hot holes. The present method performs a write operation to the non-volatile memory at lower temperatures than normal temperatures at normal use or/and at a lower operation voltage than a normal operation voltage at normal use, so as to generate a greater number of hot holes than those generated by normal write/erase operations between floating gates and drains of the memory, and then evaluates the operation of the memory while exposing it to the normal operation temperatures. This method is applicable to reliability tests of non-volatile memories such as FLASH memories.
    Type: Grant
    Filed: July 27, 2004
    Date of Patent: June 24, 2008
    Assignee: Fujitsu Limited
    Inventor: Noriyuki Matsui
  • Publication number: 20080088321
    Abstract: A method and apparatus are provided for directly measuring the ice fraction in an ice slurry. Spaced electrodes measure the electrical property of the slurry, such as capacitance across the electrodes, or alternatively conductance or other electrical characteristics. That signal is then translated into an ice fraction by a microprocessor or controller.
    Type: Application
    Filed: October 15, 2007
    Publication date: April 17, 2008
    Inventors: Yi Zheng, Ulrich Fink, Umer A. Qureshi
  • Patent number: 7304484
    Abstract: A method for the temperature compensation of a resistance measuring bridge, such as in particular a Wheatstone bridge, is characterized in that a capacitor positioned between the input circuit and a resistance switching circuit of the Wheatstone bridge is successively discharge by means of at least one Wheatstone bridge resistor. In a device for the temperature compensation of a measuring bridge, particularly a Wheatstone bridge, having a measuring bridge and a compensating resistor in the input circuit, one or two switches are located in the resistance switching circuit branch of the measuring bridge as a contact point with the latter and a capacitor is located between the input circuit and the resistance switching circuit branch.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: December 4, 2007
    Assignee: acam-messelectronic GmbH
    Inventors: Augustin Braun, Friedrich Bahnmüller
  • Patent number: 7267002
    Abstract: A capacitance type physical quantity detector includes a sensor unit of which the capacitance varies depending upon a change in the physical quantity and a C-V converter unit which converts a change in the capacitance of said sensor unit into a voltage. The C-V converter unit includes an operational amplifier, a feedback capacitor, switching means connected in parallel with said feedback capacitor, a reference voltage-generating circuit for applying a reference voltage to the operational amplifier, and a drive voltage-generating circuit for applying a drive voltage to said sensor unit. At least any one of the feedback capacitance of said feedback capacitor, the reference voltage formed by said reference voltage-generating circuit or the drive voltage formed by said drive voltage-generating circuit varies depending upon the temperature to correct temperature characteristics of the sensor unit.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: September 11, 2007
    Assignees: DENSO CORPORATION, Nippon Soken, Inc.
    Inventors: Toshikazu Itakura, Toshiki Isogai
  • Patent number: 7176700
    Abstract: A moisture sensor device includes a sensor portion having a capacitance that is varied in accordance with surrounding humidity, a signal processor for processing a detection signal of the sensor portion and outputting the signal corresponding to the humidity, a heating portion for heating the sensor portion, and a controller for controlling heating of the heating portion so that the capacitance of the sensor portion is substantially equal to a value under predetermined humidity at least during a self-diagnosis period.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: February 13, 2007
    Assignees: Denso Corporation, Nippon Soken, Inc.
    Inventors: Toshikazu Itakura, Toshiki Isogai
  • Patent number: 7100455
    Abstract: A system and method for pressure measurement may include the ability to readily produce a pressure measurement system. In one general aspect, pressure measurement may include a signal-converting circuit that includes a coupler, a signal biaser, and a signal span adjuster. The coupler is operable to receive a pressure-representative signal, and the signal biaser includes a thermally-insensitive voltage divider that facilitates biasing the pressure-representative signal. The signal span adjuster is coupled to the coupler and the signal biaser and includes a thermally-insensitive voltage divider that facilitates adjusting the span of the pressure-representative signal.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: September 5, 2006
    Assignee: Dresser-Nagano, Inc.
    Inventors: David F. Lepine, Yoshikazu Kaneko
  • Patent number: 6809528
    Abstract: A method and apparatus for measuring the water content of a liquid, including a method step for electrically measuring the property of the liquid for one parameter. The properties of the liquid are measured at least substantially simultaneously by another electrical method, where the properties of the liquid are measured using both a relative-value and an absolute-value measurement method.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: October 26, 2004
    Assignee: Vaisala Oyj
    Inventors: Lars Stormbom, Matti Lyyra, Jukka Leppänen
  • Patent number: 6750664
    Abstract: An apparatus for an integrated circuit comprising a thermal sensor (41-44), an A-D converter (58) coupled to the thermal sensor, wherein the thermal sensor provides an input to the A-D converter, and the A-D converter converts the input to a digital value representative of the thermal environment of the thermal sensor. The integrated circuit collects a data value at a location on an integrated circuit wherein the data value has a predetermined functional relationship to the temperature at the location. The integrated circuit converts the data value to a value representative of the thermal environment of the location on the integrated circuit.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: June 15, 2004
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Philippe Lance, Philippe Meunier
  • Patent number: 6690180
    Abstract: A method and sensor for determining the ratio of two components in a fluid mixture comprising a test cell in open communication with the fluid mixture and a reference cell containing a desired fluid mixture not in contact with the fluid mixture being tested, said reference and test cells having the same cell geometry. By use of a capacitance divider system, one determines the relative capacitances of said cells correlated with the dielectric constants of the respective fluid mixtures and ascertains the ratio of one component to the other component in the fluid mixture on the basis of the linear and monotonic correlation between the dielectric constant of the mixture at a given temperature and the ratio of one component to the other component. Preferably a mixture of methanol and water is tested such as for use as a feed to a reformer used in supplying hydrogen to a fuel cell. A fixed capacitor equivalent to the reference cell at a given temperature is usually substituted for the latter.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: February 10, 2004
    Assignee: HRL Laboratories, LLC
    Inventors: Robert N. Schwartz, Paul O. Braatz, Kevin W. Kirby
  • Patent number: 6570395
    Abstract: A portable grain moisture measurement device has an automatic grain moisture measurement actuation system whenever the compaction of the grain within a test cell of the device is at a preset value and upon such automatic actuation a visual display is activated to indicate that a moisture measurement is being taken as well as the sounding of an audible alarm indicating this measurement to warn the user that further compaction of the grain is unnecessary.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: May 27, 2003
    Assignee: Worens Group Inc.
    Inventors: James T. Falbo, John W. Dubay, Trent A. McElhaney
  • Publication number: 20030016030
    Abstract: A method and sensor for determining the ratio of two components in a fluid mixture comprising a test cell in open communication with the fluid mixture and a reference cell containing a desired fluid mixture not in contact with the fluid mixture being tested, said reference and test cells having the same cell geometry. By use of a capacitance divider system, one determines the relative capacitances of said cells correlated with the dielectric constants of the respective fluid mixtures and ascertains the ratio of one component to the other component in the fluid mixture on the basis of the linear and monotonic correlation between the dielectric constant of the mixture at a given temperature and the ratio of one component to the other component. Preferably a mixture of methanol and water is tested such as for use as a feed to a reformer used in supplying hydrogen to a fuel cell. A fixed capacitor equivalent to the reference cell at a given temperature is usually substituted for the latter.
    Type: Application
    Filed: May 15, 2001
    Publication date: January 23, 2003
    Applicant: HRL Laboratories, LLC
    Inventors: Robert N. Schwartz, Paul O. Braatz, Kevin W. Kirby
  • Patent number: 6501287
    Abstract: Apparatus are provided for measuring coating thickness. The apparatus include first and second inductors, which may be coils, and measuring the impedance of conductors by passing alternating current through the conductors. The conductors are arranged so that the first inductor may be positioned sufficiently close to a conductive surface so that its impedance changes and, when so positioned, any change in the impedance of the second inductor brought about by the surface is negligible compared to that in the impedance of the first. A microprocessor is provided and arranged to calculate a temperature compensated thickness measurement from the measured impedances of both inductors.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: December 31, 2002
    Assignee: Elcomenter Instruments Limited
    Inventor: Peter Ian Baldwin
  • Patent number: 6313645
    Abstract: In a method and apparatus for determining the volumetric proportion of water in snow and the density of snow, a probe consisting of at least three parallel, but differently spaced, electrical conductors is installed in an area so that the probe is surrounded by the snow, an electromagnetic signal is applied repeatedly to pairs of the conductors for determining different dielectricity coefficients, wherefrom the actual dielectricity coefficient is calculated based on probe-specific calibration data and the measuring steps are repeated with a different frequency for which the dielectricity coefficients of the water and ice are known and the volumetric parts of the snow, that is of the water, ice and air in the snow cover is calculated using the law of mass conservation.
    Type: Grant
    Filed: May 10, 2000
    Date of Patent: November 6, 2001
    Assignee: Forschungszenfrum Karlsruhe GmbH
    Inventors: Alexander Brandelik, Christof Hübner
  • Patent number: 6035004
    Abstract: An inexpensive, compact digital radio receiver corrects IQ imbalance, non-orthogonal I and Q phases, and DC offset by a DSP. The digital radio receiver is equipped with an antenna, an RF/IF converter for converting a radio frequency into an intermediate frequency, an IQ separator for separating I and Q, a filter for eliminating a noise such as a radio frequency, a multiplying sampler for sampling the output of the filter, and a digital signal processing unit mainly comprised of the DSP which implements an algorithm for estimating and correcting an IQ distortion and also performs quadrature phase demodulation. The IQ distortion can be removed inexpensively by making use of a part of a standard radio operation, hardly requiring the use of hardware for adjustment.
    Type: Grant
    Filed: November 22, 1995
    Date of Patent: March 7, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hiroshi Nakata
  • Patent number: 5764065
    Abstract: A remote contamination sensing device for contamination on insulation of electric power lines and substations includes a data logger and a supporting structure to which a sensing capacitor with at least two conductors is attached such that the conductors are spaced apart and insulated from each other. A capacitance measuring device, for measuring capacitance data between the conductors, is connected to the data logger. A hygrometer, for measuring the relative humidity of the ambient air, is also connected to the data logger. A first temperature sensor, for measuring the ambient temperature, and a second temperature sensor, for measuring the surface temperature of the capacitance sensor, are connected to the data logger. The measured capacitance data, relative humidity data, ambient temperature data, and surface temperature data are stored in the data logger.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: June 9, 1998
    Inventors: Clyde N. Richards, Joseph D. Renowden
  • Patent number: 5663650
    Abstract: A portable grain moisture meter has a large 16 character digital display allowing an alphabetical list of grain selections to be selectably displayed in full text format and subsequently tested for moisture content with the test results also displayed on the same display. The meter also has provisions for calibrating the meter to a remotely located meter and has dual temperature transducers for achieving automatic grain temperature compensation by monitoring both the grain temperature along with the cell temperature.
    Type: Grant
    Filed: August 1, 1995
    Date of Patent: September 2, 1997
    Assignee: Farmex, Inc.
    Inventor: Mike McMahon
  • Patent number: 5296819
    Abstract: A moisture sensitive device includes a polymer capacitive moisture sensitive element and a heater. The polymer capacitive moisture sensitive element is formed by sequentially stacking a lower electrode, a moisture sensitive film made of an organic polymer resin material, and an upper electrode on an insulating substrate. The heater serves to heat the moisture sensitive film to restore the original characteristics thereof.
    Type: Grant
    Filed: June 23, 1992
    Date of Patent: March 22, 1994
    Assignee: Yamatake-Honeywell Co., Ltd.
    Inventors: Takaaki Kuroiwa, Tooru Abe, Tetsuya Miyagishi
  • Patent number: 5012196
    Abstract: A capacitance sensor arrangement is used to determine the distance of an element such as a shearing handpiece from a surface such as the skin of a sheep. The arrangement processes data from one or more sensors which include a variable capacitor dependent on the distance, and provides an output voltage consistent with the distance, the output voltage being dependent on the voltage drop across a reference capacitor in the sensor circuit.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: April 30, 1991
    Assignee: The University of Western Australia
    Inventor: Jan Baranski
  • Patent number: 4952882
    Abstract: A capacitance sensor for measuring changes in thickness of a dielectric film, such as plastic film, passed through the sensor, having an upper and lower housing projecting from a back plate, the lower housing having an upper electrode surface and the upper housing having an insulator aligned with the electrode surface; the insulator having an electrode conneced to an electrical conductor; the materials for constructing the two housings, the electrode and the insulator all having a coefficient of linear temperature expansion of less than 1.times.10.sup.-6 per degree Centigrade.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: August 28, 1990
    Assignee: Modern Controls, Inc.
    Inventors: William N. Mayer, Roger Oestreich, Daniel W. Mayer