Moisture Content Or Vapor Pressure Patents (Class 73/25.04)
  • Patent number: 9010172
    Abstract: Detection system and humidity detection method for detecting volatile organic compound comprises a device for introducing clean air and a controller, wherein the device for introducing clean air is connected with a test chamber; a test chamber sheath is sleeved outside the test chamber; the test chamber is provided with a temperature sensor for detecting the temperature in the test chamber, a high-temperature test exhaust device is connected with a high-temperature exhaust pipeline of the test chamber, and a low-temperature test exhaust device is connected with a low-temperature exhaust pipeline of the test chamber; a pipeline connecting the test chamber with the low-temperature test exhaust device is also provided with a dew point sensor for detecting dew point of the air in the low-temperature exhaust pipeline; and the temperature sensor and the dew point sensor are connected with the controller.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: April 21, 2015
    Assignee: Dongguan City Simplewell Technology Co., Ltd.
    Inventors: Keyu Xia, Jiaming Zhang
  • Publication number: 20140083166
    Abstract: The apparatus has a chemical energy reservoir that releases thermal energy upon contact with moisture. The apparatus furthermore has a converter that is embodied to convert the thermal energy into electrical energy; and a circuit that is embodied to generate, operated by the electrical energy, an electrical signal for reporting the event.
    Type: Application
    Filed: February 2, 2012
    Publication date: March 27, 2014
    Inventor: Fabian Henrici
  • Publication number: 20140053628
    Abstract: A sensor system runs real-time software on the processor to receive and log temperature and humidity data from the sensors. A processor processes the data, reformats the data packaged with GPS information provided by the centralized sensor control system for transmission to the platform receiver (including error checking), and provides a diagnostic interface for displaying logged data and status information. This data is time stamped and transmitted to the centralized sensor control system across the external control/data interface.
    Type: Application
    Filed: August 27, 2013
    Publication date: February 27, 2014
    Inventors: Mary Lockhart, Thomas Wallace, Randy Brumbaugh, Malcolm Robbie, Brian Patterson, Donna Blake, Andreas Goroch
  • Publication number: 20130036794
    Abstract: Detection system and humidity detection method for detecting volatile organic compound comprises a device for introducing clean air and a controller, wherein the device for introducing clean air is connected with a test chamber; a test chamber sheath is sleeved outside the test chamber; the test chamber is provided with a temperature sensor for detecting the temperature in the test chamber, a high-temperature test exhaust device is connected with a high-temperature exhaust pipeline of the test chamber, and a low-temperature test exhaust device is connected with a low-temperature exhaust pipeline of the test chamber; a pipeline connecting the test chamber with the low-temperature test exhaust device is also provided with a dew point sensor for detecting dew point of the air in the low-temperature exhaust pipeline; and the temperature sensor and the dew point sensor are connected with the controller.
    Type: Application
    Filed: November 18, 2010
    Publication date: February 14, 2013
    Inventors: Keyu Xia, Jiaming Zhang
  • Patent number: 8172457
    Abstract: The invention relates to a method and a sensor for determining the hydrocarbon dew point in a gas, in particular in a gaseous fuel. According to the invention a roughened condensation surface is provided on a planar measurement surface of a transparent body. Light is shone onto the roughened condensation surface through the transparent body and the intensity of the light reflected back into the transparent body is measured. The hydrocarbon dew point temperature can be inferred from changes in the intensity of the light which is reflected back when heating or cooling the condensation surface.
    Type: Grant
    Filed: January 25, 2007
    Date of Patent: May 8, 2012
    Assignee: Bartec Benke GmbH
    Inventor: Alfred Boehm
  • Patent number: 8141412
    Abstract: A method of detecting the dryness of wet steam of a once-through steam injection boiler, comprises: first, by detecting and/or calculating, obtaining volume flow of wet steam, corresponding volume flow of saturated liquid, and corresponding volume flow of saturated vapour; and then obtaining the dryness of wet steam of the once-through steam injection boiler, X, according to the following relationship equation: X = ; wherein are the volume flow of wet steam, the corresponding volume flow of saturated liquid, and the corresponding volume flow of saturated vapour respectively. A detecting apparatus for detecting dryness of wet steam of a once-through steam injection boiler, specifically comprises: a data detecting module 1, a data processing module 2, and a data displaying module 3, wherein the data processing module 2 connects the data detecting module 1 and the data displaying module 3.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: March 27, 2012
    Assignee: Liaoning Shihua University
    Inventors: Baodong Chen, Longshe Shen, Yongfei Yan, Taidong Jin
  • Patent number: 8100580
    Abstract: A solution for measuring steam quality in a steam turbine is disclosed. A steam quality measurement (SQM) device and an ejector are coupled to a steam turbine through an appropriate piping configuration to draw steam emitted from the turbine through the SQM device for measurement of the steam quality, for example, continuously, during operation of the turbine.
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: January 24, 2012
    Assignee: General Electric Company
    Inventors: Scott Victor Hannula, Randy Scott Rosson, Kevin Wood Wilkes
  • Publication number: 20110000281
    Abstract: A method and apparatus for monitoring the quality of steam used in a process is disclosed. A pressure and temperature sensor is exposed to the steam on either side of an inline pressure drop device such as an orifice or pressure reducing valve. The measurements are transmitted to a controller that calculates the steam quality percentage or superheat value. An alarm is issued if the steam quality is beyond a predetermined tolerance.
    Type: Application
    Filed: July 6, 2009
    Publication date: January 6, 2011
    Inventor: Walter T. Deacon
  • Publication number: 20100319435
    Abstract: A technique facilitates the detection of moisture. The technique utilizes distributed sensor lines deployed along an insulated vessel, such as an insulated pipe. The sensor lines are used to measure temperature and to determine a differential temperature across the insulation between the sensor lines. Changes in the differential temperature can be detected, and those changes are used to determine whether moisture has intruded into a specific region of the insulation.
    Type: Application
    Filed: March 15, 2007
    Publication date: December 23, 2010
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventor: Andrew P. Strong
  • Patent number: 7794140
    Abstract: A method and system for monitoring the quality of a given gas mixture being transmitted under pressure by throttling a sample of the gas mixture to a representative pressure and measuring the hydrocarbon dew point of the sample at the representative pressure. The measured hydrocarbon dew point is indicative of the cricondentherm of the gas mixture. The representative pressure is pre-selected to provide a pre-selected margin of error between measured hydrocarbon dew points of a set of representative gas mixtures at the representative pressure and respective cricondentherms of the set of representative gas mixtures.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: September 14, 2010
    Assignee: Transcanada Pipelines Limited
    Inventors: Kamal Botros, Steve Hall, John Geerligs
  • Publication number: 20090217736
    Abstract: A method of detecting the dryness of wet steam of a once-through steam injection boiler, comprises: first, by detecting and/or calculating, obtaining volume flow of wet steam, corresponding volume flow of saturated liquid, and corresponding volume flow of saturated vapour; and then obtaining the dryness of wet steam of the once-through steam injection boiler, X, according to the following relationship equation: X = ; wherein are the volume flow of wet steam, the corresponding volume flow of saturated liquid, and the corresponding volume flow of saturated vapour respectively. A detecting apparatus for detecting dryness of wet steam of a once-through steam injection boiler, specifically comprises: a data detecting module 1, a data processing module 2, and a data displaying module 3, wherein the data processing module 2 connects the data detecting module 1 and the data displaying module 3.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Inventors: Baodong Chan, Longsho Shon, Yongio Yun, Yaldong Jin
  • Patent number: 7581877
    Abstract: A new method and apparatus is described for measurement of the dew point, and thus the vapor pressure of various gases and gas mixtures. In this method an optical element which is exposed to a gas atmosphere is cooled while its temperature is being monitored. At the same time an optical signal is sent through the back of the optical element. The optical signal goes through internal reflections. As soon as dew forms on the surface of the element, the optical signal will exhibit selective absorption due to the interaction of the evanescent tail of the optical signal and based on the chemical nature of the condensate. This invention can also be used to characterize condensable content of gas mixtures. The method allows for the spectral characterization and determination of the condensed vapor. It offers several advantages over existing methods.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: September 1, 2009
    Inventor: Sohrab Zarrabian
  • Publication number: 20090178468
    Abstract: A method for calculating moisture loss in a steam turbine operating under wet steam conditions.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 16, 2009
    Inventors: Tao Guo, Douglas C. Hofer, William J. Summer
  • Publication number: 20090064767
    Abstract: Method for ascertaining an ethanol content of a fuel with the steps: ascertaining the vapor pressure of the fuel, ascertaining the temperature of the fuel and ascertaining the ethanol content of the fuel as a function of the vapor pressure and the temperature, which were ascertained.
    Type: Application
    Filed: September 8, 2008
    Publication date: March 12, 2009
    Applicant: Robert Bosch GmbH
    Inventor: Peter ROTH
  • Publication number: 20090038376
    Abstract: An apparatus for measuring moisture in a gas flowing in one direction through an enclosed chamber includes a moisture sensor placed in the chamber. The moisture sensor includes a first and second electrode supported by a non-conductive member. Each of the first and second electrode has at least one elongated finger and a coating made of a moisture absorbing material. At least one elongated finger of the first electrode is substantially parallel with at least one finger of the second electrode. The apparatus further includes a gas temperature sensor, a moisture sensor temperature sensor, and a cooling element for controlling the temperature of the moisture sensor based on the data from the gas temperature data and moisture sensor temperature data. Further, the apparatus includes a source of electrical current providing a voltage across the first and second electrode.
    Type: Application
    Filed: August 6, 2007
    Publication date: February 12, 2009
    Inventors: DIMITRY PETROSYAN, Nikolay A. Petrosyan
  • Patent number: 7474965
    Abstract: A system and method for identifying molecules. Molecules are identified from a gaseous matter having the molecules and flowing at two different flow rates. A system and method for identifying a substance. A particle which is indicative of a substance is identified from matter having the particle and flowing at two different flow rates. After the particle is identified, the substance is identified.
    Type: Grant
    Filed: April 5, 2005
    Date of Patent: January 6, 2009
    Assignee: The Regents of the University of California
    Inventors: Bradley Johnson, Rehan M. Khan, Noam Sobel
  • Patent number: 7416331
    Abstract: A measuring device for detecting a humidity and temperature of a window surface including at least one moisture sensor and at least one temperature sensor placed on the window surface, an evaluation unit connected downstream from the moisture and temperature sensors, and a signal converting and linking unit placed between the moisture and temperature sensors and the evaluation unit. Further, when the temperature sensor detects a change in a temperature of the window surface or the moisture sensor detects a change in a moisture of the window surface, a frequency of an oscillator included in the signal and converting unit is changed.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: August 26, 2008
    Assignee: Preh GmbH
    Inventors: Anton Rüttiger, Markus Peschel
  • Patent number: 7380980
    Abstract: The long-side surface of a triangular prism is a detection surface. The distal end portions of coaxial light-emitting/light-receiving optical fiber cables are joined to one short-side surface of the prism. A thermoelectric cooling element is mounted on the other short-side surface of the prism. A mirror is provided between the cooling surface of the thermoelectric cooling element and the short-side surface. When dew condensation occurs on the detection surface, part of light applied from an optical fiber on the light-emitting side onto the lower surface of the detection surface exits from the prism through the condensed dew. The specular reflection returns to the lower detection surface by a mirror surface and is specularly reflected again. The specular reflection then enters an optical fiber on the light-emitting side. Dew condensation on the detection surface is detected by a change in the intensity of light received through the optical fiber.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: June 3, 2008
    Assignee: Yamatake Corporation
    Inventors: Yoshiyuki Kanai, Kazumasa Ibata, Masaki Takechi, Shingo Masumoto, Yasuhiro Kajio, Shigeki Shoji, Ryu Akimoto
  • Patent number: 7368291
    Abstract: A process is provided for determining the amount of sulfuryl fluoride in the atmosphere of an enclosed area that has been fumigated with sulfuryl fluoride (SO2F2). This process comprises: (A) sampling said atmosphere of said enclosed area to obtain a gaseous sample; (B) selectively removing water from said gaseous sample by passing said gaseous sample through a perevaporation zone to obtain a perevaporated sample, wherein said perevaporation zone comprises a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid; and (C) analyzing said perevaporated sample in a sulfuryl fluoride detector to determine the amount of sulfuryl fluoride in said perevaporated sample.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: May 6, 2008
    Assignee: Dow AgroSciences LLC
    Inventors: Malcolm Wayne Warren, James Lawrence Witt
  • Patent number: 7360396
    Abstract: In a gas sensor, at least three levels of current are supplied to a heating element successively in a step-like manner for a predetermined time period. An arithmetic unit receives both-end voltages of the heating element for the respective current after elapse of the predetermined time period and calculates temperature from the both-end voltage of the heating element obtained when the lowest current flows. Then, the arithmetic unit corrects the both-end voltages of the heating element using the calculated temperature, a zero-point correction equation and a sensitivity correction equation to obtain respective standardized output values. Subsequently, the arithmetic unit calculates humidity based on the difference between the standardized output values, and corrects the standardized outputs based on the calculated humidity and humidity correction equations. By this method, the arithmetic unit calculates concentration of detection target gas.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: April 22, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Rihito Shoji
  • Patent number: 7257985
    Abstract: Methods and apparati for measuring entrained gas content. One of the disclosed apparatus embodiments includes a chamber and piping for process fluid, the piping including two different sectors each comprising a density and temperature gauge having a pressure gauge located upstream and a second pressure gauge located downstream, the two sectors being operatively joined together by a pressure-changing device. The pressure measurement feature may be incorporated into the combination density and temperature gauge, eliminating the need for separate pressure gauges. Data generated by this invention reduces measurement error caused by the dissolving or exsolving of gases with changes in pressure of a fluid, while providing instantaneous measurement, through apparatuses that measure system conditions at each of two pressure states within a very short period of time. For instance, in the context of continuously coating a substrate, the method of this invention comprises: a.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: August 21, 2007
    Assignee: Appleton Papers Inc.
    Inventors: Robert Josef Franda, Qingyuan Chen
  • Patent number: 7062968
    Abstract: A temperature control apparatus for a humidity sensor is provided for preventing impurities from sticking on a sensor element, while protecting the sensor element from cracking due to the humidity sensor heated by a heater in the presence of condensation, to maintain a high detection accuracy of the humidity sensor. The temperature control apparatus is configured to control the temperature of a sensor element of a humidity sensor disposed in an exhaust passage of an internal combustion engine for detecting the humidity within the exhaust passage. The temperature control apparatus comprises a heater for heating the sensor element, a temperature sensor for detecting the temperature of the sensor element, and an ECU for controlling a heating amount of the heater to bring the detected temperature of the sensor element to a first predetermined temperature during an operation of the internal combustion engine.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: June 20, 2006
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Masaki Ueno, Kei Machida, Tetsuo Endo, Hideharu Yamazaki
  • Patent number: 7059170
    Abstract: A method and apparatus for measuring relative humidity of a mixture that provides a quick response time for thermal lag while affording protection to fragile sensors. In one aspect, the invention is an apparatus comprising: a chamber having a membrane covering an opening in the chamber, the membrane being permeable to water vapor while impermeable to liquid water; a humidity sensor for measuring relative humidity of the mixture within the chamber; a first temperature sensor for measuring a temperature relating to the mixture within the chamber; a second temperature sensor for measuring temperature of the mixture at a point exterior to the chamber; and a processor for receiving signals representing the measurements taken by the humidity sensor, the first temperature sensor, and the second temperature sensor and programmed to calculate relative humidity of the mixture at the point exterior to the chamber as a function thereof.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: June 13, 2006
    Assignee: Nielsen-Kellerman, Inc.
    Inventors: Richard Kellerman, Paul H. Nielsen
  • Patent number: 7028530
    Abstract: There is provided a gas detector capable of detecting hydrogen concentration and humidity independently in the environment containing both hydrogen and water vapor. The gas detector comprises a high-temp exothermic detector unit and a low-temp exothermic detector unit provided with themosensitive resistors of different self-heating temperatures. The gas detector converts gas-level outputs produced by the high-temp exothermic detector unit and the low-temp exothermic detector unit responsive to the hydrogen concentration and humidity into electric signals, and outputs them after computing electrically levels of the hydrogen concentration and humidity contained in a gas introduced into the two detector units through a gas intake opening.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: April 18, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuharu Katsuki, Rihito Shoji, Masaki Tada, Junichi Yukawa
  • Patent number: 7017388
    Abstract: Improved control of continuous processes that handle liquids. Data generated by this invention is used to control gas contents of liquids within optimum ranges, for instance in paper coating processes and in the manufacture of food products (ketchup), personal care products (shampoo), paints, and in any industry where information on entrained and/or dissolved gases, and related parameters such as true density of and gas solubility in process liquids, is employed to optimize processing. The amount of gas in a liquid is determined by subjecting a mixture of an incompressible liquid sample and a compressible gas to three or more different equilibrium pressure states, measuring the temperature and volume of the mixture at each of the pressure states, determining the changes in volume of the mixture between at least two different pairs of pressure states, and calculating the amount of gas in the liquid sample.
    Type: Grant
    Filed: May 10, 2004
    Date of Patent: March 28, 2006
    Assignee: Appleton Papers, Inc.
    Inventors: Qingyuan Chen, Robert Josef Franda
  • Patent number: 6883366
    Abstract: A vapor sensor is disclosed, which includes a substrate containing a sensing element, wherein the substrate is located proximate to a sleeve portion which covers and protects the sensing element. The vapor sensor also includes a vapor filter or permeable membrane affixed to an end of the sleeve portion, wherein the end of the sleeve portion is located opposite the sensing element. A housing and a cover are also provided, such that the housing retains the substrate and the cover snaps onto the housing. The housing itself includes walls from which a hole is formed through which vapors may pass. The vapor sensor can be mounted to a gas water heater in such a manner as to reduce air flow to the sensing element and prevent tampering of the vapor sensor unit itself.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: April 26, 2005
    Assignee: Honeywell International Inc.
    Inventors: Richard W. Gehman, Todd H. Sellman, Richard C. Cholke, Michael R. Hoefer
  • Patent number: 6836732
    Abstract: An apparatus and method for ensuring effective and efficient vehicle vapor recovery performance, storage tank system integrity relative to both vapor and liquid containment and for reducing the probability that inaccurate information causes companies to undertake unnecessary, expensive and wasteful loss investigations at gasoline dispensing facilities. A fuel storage and delivery system is transformed from an “open system” communicating directly with the environment to a “closed system” which ensures capture, containment and accurate accounting of both hydrocarbon vapors and liquid phase product.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: December 28, 2004
    Assignee: Arid Technologies, Inc.
    Inventor: Tedmund P. Tiberi
  • Patent number: 6766680
    Abstract: Improved control of continuous processes that handle liquids. Data generated by this invention is used to control gas contents of liquids within optimum ranges, for instance in paper coating processes and in the manufacture of food products (ketchup), personal care products (shampoo), paints, and in any industry where information on entrained and/or dissolved gases, and related parameters such as true density of and gas solubility in process liquids, is employed to optimize processing. The amount of gas in a liquid is determined by subjecting a mixture of an incompressible liquid sample and a compressible gas to three or more different equilibrium pressure states, measuring the temperature and volume of the mixture at each of the pressure states, determining the changes in volume of the mixture between at least two different pairs of pressure states, and calculating the amount of gas in the liquid sample.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: July 27, 2004
    Assignee: Appleton Papers, Inc.
    Inventors: Qingyuan Chen, Robert Josef Franda
  • Patent number: 6732568
    Abstract: A sensor probe and method of use for determining the temperature, velocity, and/or liquid volumetric fraction of gas laden with droplets. In one variation, the probe includes a single heating element used in a well-characterized flow. The heating element is maintained above the Leidenfrost transition for the droplets, which prevents cooling effects from the droplets from impacting the temperature measurement. In another variation, the probe includes two or more heating elements arranged in similar flow environments. The property of interest is derived by relying on thermodynamic and heat transfer principles, which are not usable in conjunction with conventional devices.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: May 11, 2004
    Assignee: University of Maryland
    Inventors: Marino Dimarzo, Paolo Ruffino
  • Patent number: 6612154
    Abstract: Systems and methods for monitoring a heat treating atmosphere derive from at least one sensor placed in situ in the atmosphere a process variable, which is indicative of the ratio of gaseous hydrogen H2(g) to water vapor H2O(g) in the atmosphere. The systems and methods use the process variable, e.g., to control the atmosphere, or to record, or display the process variable.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: September 2, 2003
    Assignee: Furnace Control Corp.
    Inventors: Robert N. Blumenthal, Andreas T. Melville
  • Patent number: 6604406
    Abstract: A preconcentrator system and apparatus suited to human portable use wherein sample potentially containing a target chemical substance is drawn into a chamber and through a pervious screen. The screen is adapted to capture target chemicals and then, upon heating, to release those chemicals into the chamber. Chemicals captured and then released in this fashion are then carried to a portable chemical detection device such as a portable ion mobility spectrometer. In the preferred embodiment, the means for drawing sample into the chamber comprises a reversible fan which, when operated in reverse direction, creates a backpressure that facilitates evolution of captured target chemicals into the chamber when the screen is heated. The screen can be positioned directly in front of the detector prior to heating to improve detection capability.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: August 12, 2003
    Assignee: Sandia Corporation
    Inventors: Kevin L. Linker, Charles A. Brusseau, David W. Hannum, James G. Puissant, Nathan R. Varley
  • Publication number: 20030115933
    Abstract: A system for monitoring concentrations of sterilant, such as hydrogen peroxide vapor, within a sterilization apparatus, includes a self-contained, sterilant monitoring assembly that is freely positionable within the sterilization apparatus. The assembly includes a gas-detecting sensor and associated temperature sensor mounted on a portable structure, as well as a suitable data collection circuit for receiving output signals from the sensors. The assembly also includes signals connectors, such as a physical data port or a remote transmitter, or both. Signals can be transmitted concurrently with data collection, or an electronic memory may be provided for subsequent transfer of the collected data. Collected data is transferred to a remote communication unit positioned exteriorly of the sterilization apparatus.
    Type: Application
    Filed: February 4, 2003
    Publication date: June 26, 2003
    Inventors: Jianjun Wang, David A. Mondiek
  • Patent number: 6439028
    Abstract: A method and equipment for measuring vapor flux from a surface e.g. the rate of water loss from human skin which is useful in the evaluation of the efficiency of the skin/water barrier uses a closed cylinder which is placed with the open end against the skin and the closed end is cooled. By measuring the temperature and relative humidity within the cylinder the water vapor flux can be determined.
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: August 27, 2002
    Assignee: South Bank University Enterprises Limited
    Inventor: Robert E. Imhof
  • Patent number: 6276202
    Abstract: A device for detecting snow and ice which has a humidity sensor and an ambient temperature sensor. An evaluator switch is controlled according to a humidity sensor-measured variable, producing a control signal at set humidity values for defrosting a surface which is being monitored for snow and ice. The ambient temperature sensor activates the humidity sensor within a temperature range of between +2° C. and −12° C. The humidity sensor itself has a PTC (positive temperature coefficient) heating element. The current consumption of the heating element is used as a measure of humidity. Both the ambient temperature sensor and the humidity sensor are positioned at a mutual distance in a longitudinally extended sensor cartridge made of plastic. The temperature sensor is thermally decoupled from the PTC heating element. The PTC heating element is built into a metal sleeve in such a way that it is corrosion and humidity proof.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: August 21, 2001
    Assignee: Tekmar GmbH
    Inventor: Hans Latarius