Abstract: A method for sensing gas composition and gas pressure, based on the thermal constants of a variable electrical resistor, is presented. The method for sensing gas composition and pressure includes monitoring a variable electrical resistor whose dynamic thermal response is determined by the thermal conductivity and thermal capacity of the surrounding gas of a given atmospheric environment. In the thermal domain, the sensor has a low-pass characteristic, whose phase delay is determined by the thermodynamic characteristics of the surrounding gas such as composition and pressure. The method can be used for sensing gas composition and can also be used for sensing gas pressure.

Abstract: A tubular heater includes a continuous heat-generating resistance element formed in a predetermined pattern on one surface of a tubular insulating substrate, and first and second lead wires connected opposite ends of the heat-generating resistance element and extending from one end of the tubular insulating substrate in a common axial direction of the tubular insulating substrate. The first and second lead wires are disposed in diametrically opposed relation to each other about a central axis of the tubular insulating substrate.

Abstract: Thermal conductivity detectors and methods of operating thermal conductivity detectors are described herein. One or more device embodiments include a single fluidic channel, wherein the single fluidic channel includes a single inlet and a single outlet, and multiple sensors configured to determine one or more properties associated with a thermal conductivity of a fluid in the single fluidic channel.

Abstract: An interior space of the at least one housing of a force-measuring device is filled with a gas composition that is distinguishable in at least one parameter from the ambient atmosphere. A sensor that is arranged in the interior space, or on the housing, measures this distinguishable parameter. A processing unit of the force-measuring device compares signals obtained from the sensor to monitor and determine the condition of the force-measuring device.

Abstract: A gas sensor includes a substrate having a low thermal conductivity. Localized heating can be produced using a serpentined heater carried by the substrate. The low thermal conductivity of the substrate substantially confines the generated heat to a region local to the heater thereby reducing required power to operate the sensor. Multiple sensing elements can be deposited onto the substrate adjacent to respective heaters and relatively close together because of the thermal isolation provided by the substrate. In one embodiment, the sensor can include the ceramic substrate, the heater, catalytic material overlying the heater with a gas impermeable layer overlying, at least in part the catalytic material.

Abstract: A calorific value calculation formula generating system is equipped with a measuring mechanism for measuring heat dissipation constant values or thermal conductivity values of each of plural mixed gases each containing plural kinds of gas components at plural temperatures; and a formula generation module for generating a calorific value calculation formula having heat dissipation constant or thermal conductivities at the plural temperatures as independent variables and a calorific value as a dependent variable on the basis of calorific value values of the plural mixed gases and the heat dissipation constant values or the thermal conductivity values measured at the plural temperatures.

Abstract: The present invention provides a high-responsiveness and high-accuracy thermal gas sensor configured to enable gas to be analyzed based on a variation in heat conductivity. The thermal gas sensor includes a substrate 2 with a cavity portion 5, a thin-film support 6 stacked in the cavity portion and comprising a plurality of insulating layers 8a and 8b, and a first heating member 3 and a second heating member 4 both sandwiched between the insulating layers in the thin-film support. The second heating member is located around a periphery of the first heating member. The first heating member is controlled to a temperature higher than a temperature to which the second heating member is controlled. The concentration of ambient gas is measured based on power applied to the first heating member.

Abstract: A particle sensor including a diaphragm, a diaphragm heater, and at least two measuring electrodes situated on the diaphragm, for electrical conductivity measurement, the diaphragm having a thickness of less than or equal to 50 ?m, in order to allow a calorimetric particle quantity determination.

Abstract: A thermal conductivity detector includes a structure defining a cavity, the structure principally comprising a material having a first coefficient of thermal expansion; a sensing element for sensing a thermal conductivity of a gas flowing within the cavity, the sensing element having a second coefficient of thermal expansion different from the third first coefficient of thermal expansion, the sensing element being disposed at least in part within the cavity; and a compensation structure having a third coefficient of thermal expansion different from the first and second thermal coefficients of expansion. Over a selected temperature range, a stress within the sensing element is less than a yield stress of any component of the sensing element, and a stress within the compensation structure is less than a yield stress of any component of the compensation structure.

Abstract: A heat radiation coefficient C [=Ph/(Th?To)] from a microheater is calculated in accordance with a power Ph applied to the microheater which is supported in air and provided in an ambient gas, a heater temperature Th, and an ambient temperature To at this moment. Further, a thermal conductivity ?(T) of the ambient gas is obtained from the calculated heat radiation coefficient C based on a proportional relation [C=K·?(T)] between a thermal conductivity ?(T) of the ambient gas and the heat radiation coefficient C at a measurement temperature T [=(Th?To)/2].

Abstract: A method for detecting a ratio of a first substance to that of a second substance in a mixture of substances, includes generating heat in a heating element; measuring a temperature proximate to the heating element; and calculating the ratio of the first substance to that of the second substance from the temperature. In some embodiments, the ratio of the concentrations of hydrogen and chlorine in a mixture of hydrogen and chlorine may be determined.

Abstract: An automatic drying apparatus and a method of controlling the same is disclosed, enabling exact drying by using a humidity sensor (37) provided at a location having a stabilized output characteristic for automatic drying, the automatic drying apparatus including a heating apparatus (31) for heating air supplied into a drum into which a drying object is introduced, a fan (32) for forcibly drawing air into the drum; and a humidity sensor (37) provided between the fan (32) and the heating apparatus (37) such that a sensing surface is positioned to be parallel to a flowing direction of air passed through the fan (32), for outputting a sensing voltage value for determining dryness of the drying object.

Abstract: A fluid identification device of long life for identification of a target fluid. The device uses at least two liquid type detection parts each of which is equipped with both of a temperature detector and a heating element, selects electrical conduction to any one of the heating elements, and identifies the target fluid based on a fluid temperature detection signal of the temperature detector in the fluid detection part not including the heating element whose electrical conduction has been selected and an output of the fluid type detection circuit.

Abstract: The measurement sensitivity is improved by suppressing the surrounding temperature influence as much as possible, while realizing scale reduction, and by enlarging the detection signal, while reducing the production errors in enclosing a reference gas. Provided is a thermal conductivity sensor that detects thermal conductivity of a sample gas by using a Wheatstone Bridge circuit constructed in such a manner that measurement resistors that are brought into contact with the sample gas are disposed on a first side, and reference resistors that are brought into contact with a reference gas are disposed on a second side, and comparing the potential difference between connection points of the reference resistors and the measurement resistors. The measurement resistors disposed on the first side are assembled in one measurement space, and the reference resistors disposed on the second side are assembled in one reference space.

Abstract: Provided is a detection unit mold package (2A), which is equipped with plate-shaped protrusions (21P and 22P) to contact an object liquid so as to exchange the heat with the object liquid. The plate-shaped protrusions (21P and 22P) are formed by sealing a liquid-kind detecting unit (21a) and a liquid-temperature detecting unit (22a), which are made of thin-film chips containing at least temperature-sensitive elements, and metallic die pads (21c and 22c) having those detecting units joined thereto, with a sealing material (23), so that they may not be exposed to the surface. The plate-shaped protrusions (21P and 22P) have their two principal planes in parallel with the metallic die pads (21c and 22c).

Abstract: The invention relates to a miniaturized gas chromatography module, comprising: a gas injector unit having a gas injector sample inlet and outlet, the gas injector inlet being connectable with a source of a substance to be analysed, a separation column having a separation column inlet and outlet, the separation column inlet being in fluid communication with the gas injector sample outlet, a thermal conductivity sensor having a sensor inlet and outlet, the sensor inlet being in fluid communication with the separation column outlet. The invention addresses the problem to broaden the field of application of such gas chromatography module.

Abstract: An assembly and method for gas analysis. The assembly comprises a catalyst compartment for catalytically reacting a component of a gas sample, producing one or more gas species as products. A product compartment receives the gas species, and a sensing element within the compartment senses the amount of one or more of the gas species. This amount is compared to the amount of the same gas species present in a reference compartment containing a non-catalyzed gas sample, providing the amount of the gas species produced by catalysis. Using this value, the content of the gas component in the gas sample is calculated based upon the stoichiometry of the catalyzed reaction. In preferred embodiments, the gas for analysis is a process gas for fuel production, and the catalyst is a high temperature shift catalyst that catalyzes the reaction of carbon monoxide and water into hydrogen and carbon dioxide.

Abstract: A method and apparatus for two-dimensional gas chromatography (GC), including a valve having first and second positions (P1, and P2), and first through fourth sample flow paths (FP1-FP4). In P1, a first gas sample is collected from a first dimension GC column via FP1, a first pressure source and a first, second dimension GC column are connected via FP2, a second pressure source and a second, second dimension GC column are connected via FP3, and FP4 is disconnected. In P2, the first sample in FP1 is introduced to the second, second dimension GC column via FP1, with aid of the second pressure source, a second gas sample is collected from the first dimension GC column via FP2, the first pressure source and the first, second dimension GC column via FP4 are connected, and FP3 is disconnected.

Abstract: A method for sensing gas composition and gas pressure, based on the thermal constants of a variable electrical resistor, is presented. The method for sensing gas composition and pressure includes monitoring a variable electrical resistor whose dynamic thermal response is determined by the thermal conductivity and thermal capacity of the surrounding gas of a given atmospheric environment. In the thermal domain, the sensor has a low-pass characteristic, whose phase delay is determined by the thermodynamic characteristics of the surrounding gas such as composition and pressure. The method can be used for sensing gas composition and can also be used for sensing gas pressure.

Abstract: A physical gas sensor of thermal type capable of determining the concentrations of a gas mixture even in the presence of humidity by measuring the thermal diffusivity and conductivity includes a cell with thermal conductivity whose frequency response to the gases is known, in particular in respect of humidity, delivering a signal Vm representative of the concentration of the gas. This cell is excited by a pulsed signal so that a processing can be carried out at different analysis frequencies: at low frequency and at higher frequency. The output signals from the two processing chains are combined in the circuit (60) so as to provide the levels of concentration of the gas and the concentration of the water vapour. The signals obtained may also be re-combined together with components of the signal Vm of various passbands.

Abstract: The invention proceeds from a diesel cycle internal combustion engine that can be operated with a fuel having a low ignition point and a fuel having a higher ignition point, with at least one fuel tank (1), with a fuel pump (7), with a high-pressure pump (11), with an injection system (12) and with an electronic controller (17) in which different control parameters for operation with the fuel having the low ignition point and for operation with the fuel having the higher ignition point are stored. According to the invention, control parameters (19, 20) for the start of injection are stored in the electronic controller (17), wherein the start of injection for the fuel having the higher ignition point is retarded relative to the start of injection for the fuel having the low ignition point exclusively in the high-load range or exclusively in the medium-load and high-load ranges.

Abstract: Hotwire element for thermal conductivity detectors, that comprises one or two individual nickel filaments each having resistance of above 200 ohm at 20° C. and an insulation coating of polytetrafluoroethylene with a thickness less than 5 micrometers, that are wound into a uniformly filled spherical or cylindrical body that has at least 33% gas-permeable hollow volume. Relevant hotwire sensor for thermal conductivity detectors, that comprises a wound on a centering holder filled element enveloped by fixed fillers forming a symmetric to it built-in cavity with an inlet and a gas outlet surrounding the centering holder. Radii of the filled elements and their cavities are in proportion, at which minimum electric current is needed for heating the elements to desired temperature.

Abstract: An interior space of the at least one housing of a force-measuring device is filled with a gas composition that is distinguishable in at least one parameter from the ambient atmosphere. A sensor that is arranged in the interior space, or on the housing, measures this distinguishable parameter. A processing unit of the force-measuring device compares signals obtained from the sensor to monitor and determine the condition of the force-measuring device.

Abstract: A heat radiation coefficient C [=Ph/(Th?To)] from a microheater is calculated in accordance with a power Ph applied to the microheater which is supported in air and provided in an ambient gas, a heater temperature Th, and an ambient temperature To at this moment. Further, a thermal conductivity ?(T) of the ambient gas is obtained from the calculated heat radiation coefficient C based on a proportional relation [C=K·?(T)] between a thermal conductivity ?(T) of the ambient gas and the heat radiation coefficient C at a measurement temperature T [=(Th?To)/2].

Abstract: A method of determining properties of a formation fluid based on measurements of fluid sound speed, a measurement of fluid density, or both. The properties include compressibility, thermal conductivity, and gas oil ratio. The compressibility of a fluid is equal to the reciprocal of the product of the sound speed squared and fluid density. The density and the sound speed can be measured acoustically. The method further includes a manner of processing data including applying the Savitzky-Golay method and utilizing a variable thresholding technique.

Abstract: To provide a gas sensor chip, and a gas sensor provided therewith, capable of producing stable output characteristics over an extended period of time even when installed in a harsh environment such as a boiler smokestack carrying exhaust gasses. There is a backside structure wherein a catalyst carrier that contacts a gas to be measured is disposed on one side of a thermal conductor, a temperature sensing portion is disposed in a location that does not contact the gas to be measured, on the other side of the thermal conductor, and the temperature sensing portion measures the temperature corresponding to the temperature of the catalyst carrier through the thermal conductor, to enable the sensing of the amount of flow over an extended period of time without the temperature sensing portion being negatively affected by the gas to be measured.

Abstract: A portable, relatively low power gas detector incorporates a single pellistor-type sensor for sensing an explosive gas of interest. Outputs from the sensor are corrected in accordance with ambient temperature and humidity and pre-stored correction factors based on characteristics exhibited by a plurality of similar sensors.

Abstract: A process is provided for measuring a gas concentration with at least one thermal measuring element. The thermal measuring element is operated by pulses. A measured value of the gas concentration in the environment of the measuring element is obtained from the evaluation of the response of the measuring element to at least one single pulse by determining transient states of the thermal measuring element. From this the measured value of the gas concentration in the environment of the measuring element can be derived, during the imposed pulse based on electric measured variables.

Abstract: A system and related method are provided to calibrate for wire capacitance during use to minimize error in conductivity measurement of the target fluid. The system includes a signal generator configured to drive the conductivity cell and the temperature element, with an alternating current (AC) drive signal having variable parameter. The system further includes a processor assembly electrically coupled to the conductivity cell and the temperature element to calculate a conductivity value of the fluid. The conductivity value is a function of the values of the temperature measurement, the compensation measurement, and the raw conductivity measurement, thereby compensating the conductivity value for capacitance effects. In this manner, the system effectively compensates for capacitance attributable to wiring extending between the electrode and other electronics of the sensor, usable with wiring of varied and unknown lengths.

Abstract: A gas sensor includes a substrate having a low thermal conductivity. Localized heating can be produced using a serpentined heater carried by the substrate. The low thermal conductivity of the substrate substantially confines the generated heat to a region local to the heater thereby reducing required power to operate the sensor. Multiple sensing elements can be deposited onto the substrate adjacent to respective heaters and relatively close together because of the thermal isolation provided by the substrate. In one embodiment, the sensor can include the ceramic substrate, the heater, catalytic material overlying the heater with a gas impermeable layer overlying, at least in part the catalytic material.

Abstract: A system and methodology for the trace detection of organic explosives is described. The detector system combines a separation system, such as a gas chromatograph to separate the components of an explosive mixture, with a pyrolysis detector. In operation, effluent from the separation system is pyrolyzed and the fragments produced on pyrolysis of the explosive compound are then detected. The small molecule fragments exhibit sharply banded, characteristic spectrum, enabling detection of the explosive materials. The system is tested using the explosive materials nitrobenzene and 2,4-dinitrotoluene, and with the nitramine explosive tetryl. Detection limits are 25 ng for nitrobenzene, and 50 ng for 2,4-dinitrotoluene. Tetryl is detected with a detection limit of 50 ng.

Abstract: A contact combustion-type gas sensor that can maintain its initial sensitivity over a long period of time in the presence of silicon vapor, wherein an induction portion 5 of a gas detecting element 1 contains not less than 30 percent by weight of an oxidation catalyst, and is aged in advance in an environment that contains silicon vapor serving as a poisoning substance.

Abstract: A micro fluid analyzer that may be highly sensitive, fast and very compact. The analyzer may use sufficiently low power per analysis to be easily implemented with an equivalently small battery pack or other portable power source. There may be energy conservation features in the analyzer, such as optimal adsorber film thicknesses in the pre-concentrator, concentrator and chromatographic separators. There may be special timing of the phased heating elements in the concentrators and separators to further reduce energy consumption. Various kinds of detectors and sensors may be incorporated in the analyzer for achieving low probability for false positives and detection versatility. There may be a controller that provides data acquisition and analyses, drive signals for control, management of wireless signal transmission and reception, processing, and other operational uses of the micro analyzer.

Abstract: A gas measuring device for measuring a presence of a target gas in a fluid medium includes a sensor having a sensing element and a heating element being configured to heat the sensing element to a predetermined operating temperature. The sensing element is responsive to the target gas such that at least one electrical property of the sensing element varies based on a presence of the target gas, and the electrical property of the sensing element is measured by the gas measuring device. The gas measuring device also includes a control circuit having a heating element controller connected to, and measuring an electrical property of, the heating element. The control circuit also includes a heater power supply supplying power to the heating element, wherein the heating element controller is connected to, and controls the operation of, the heater power supply based on the measurement of the electrical property of the heating element.

Abstract: A micromechanical thermal-conductivity sensor is provided which includes a thermally insulated diaphragm formed by a recess in a base plate exhibiting poor thermal conductivity. At least one heating element is applied on the diaphragm, at least one temperature-dependent electrical resistor is applied on the diaphragm for measuring the temperature of the diaphragm, as well as at least one further temperature-dependent electrical resistor is applied outside of the diaphragm on the base plate for measuring the ambient temperature. On one or both of its sides, the diaphragm is covered by a porous cover plate permitting gas exchange by diffusion, a cavity being left open between the diaphragm and the porous cover plate.

Abstract: A gas sensor includes a gas detection chamber into which a detection gas is introduced, a detecting element and a compensating element each disposed in the gas detection chamber, a detection device which detects the concentration of a detection target gas contained in the detection gas, in accordance with a difference in electrical resistance values between the detecting element and the compensating element, and a dehumidifying element which is provided in the gas detection chamber, and reversibly absorbs water contained in the detection gas and drains off the water absorbed in the dehumidifying element.

Abstract: Embodiments of the present invention relate a gas sensor system comprising a gas generating device adapted to generate a test gas, a target gas sensor positioned near the gas generating device, a test gas sensor positioned near the gas generating device and in communication with the target gas sensor and wherein the test gas sensor is sensitive to the test gas.

Abstract: An apparatus, system, and method are disclosed for determining a catalyst bed temperature. The method may include receiving a current fluid mass flow within an exhaust pipe and a total amount of unburned fuel available for catalytic combustion. The method may further include determining a plurality of fluid enthalpy values corresponding to various locations within the exhaust pipe. The method may continue with calculating an amount of fuel burned on an upstream catalyst based on the plurality of fluid enthalpy values, and determining an amount of fuel remaining that is available for combustion on a downstream catalyst. The method may determine a combustion efficiency of the downstream catalyst based on the temperature rise across the downstream catalyst, and an amount of heat generated within the downstream catalyst based on the combustion efficiency and the amount of fuel remaining that is available for combustion on the downstream catalyst.

Abstract: The invention relates to a device and methods for characterizating flowing substances, liquid or gas. The device includes: a transport duct with a heating or a cooling element; a temperature difference sensor having a temperature measurement cell downstream of the heating or cooling element and means to determine a temperature difference in the flowing substance upstream and downstream of the heating or cooling element; a flow control means having flow measurement means for measuring a mass flow characteristic and a flow correction means for correcting for measured mass flow variations; and an evaluation means for evaluating a characterizing feature of the flowing substance comprising a function relating temperature differences measured on one or more calibration substances to one or more characterizing features of the flowing substance. Various embodiments relate to the related use and methods of the device for identification and control of the flowing substance.

Abstract: A gas sensor which includes walls delimiting a gas detection chamber, and having an introduction port (or an inlet) through which an observed gas is introduced into the gas detection chamber, a measuring element disposed in the gas detection chamber and measuring concentration of a subject gas contained in the observed gas, and a heater constituting at least a portion of the walls, the portion facing the gas detection chamber.

Abstract: The present invention relates to the method and equipment for inspecting nuclear experimental locales, and particularly relates to the method and system for separating and measuring 37Ar quickly. The method of the invention comprises the steps of sampling, eliminating impurities, separating, purifying, measuring the sum of Ar, collecting Ar, measuring the activity of 37Ar, etc. The control unit in the system of the invention connects respectively to a sampling unit, a separating-purifying unit, and a radioactivity measuring unit which are connected in turn, and a computer and the software of the control unit are in charge of the automatic operation, measurement and data-collection of the whole system. The method and system for quickly separating and measuring 37Ar of the patent can meet the requirements of locales inspection for Comprehensive Test Ban Treaty (CTBT), the sensitivity of measuring 37Ar is high, so do the production and purity of Ar.

Abstract: An apparatus includes a detection element having a detection element property that changes when exposed to a corrosive substance, a testing device coupled to the detection element, the testing device configrued to measure the detection element property, and a processor in communication with the testing device, the processor configured to indicate the presence of the corrosive substance using the detection element property. In an embodiment, the detection element is metal and the detection element property is resistivity. In another embodiment, the apparatus further includes a comparison element coupled to the testing device and shielded from the corrosive substance, the comparison element having a comparison element property, and wherein the processor is configured to compare the detection element property to the comparison element property to determine whether the detection element property is within a predetermined range of the comparison element property.

Abstract: A process is provided for measuring a gas concentration with at least one thermal measuring element. The thermal measuring element is operated by pulses. A measured value of the gas concentration in the environment of the measuring element is obtained from the evaluation of the response of the measuring element to at least one single pulse by determining transient states of the thermal measuring element. From this the measured value of the gas concentration in the environment of the measuring element can be derived, during the imposed pulse based on electric measured variables.

Abstract: A process for protecting a filament in a thermal conductivity detector from chemical corrosion includes changing the flow direction of the column effluent in the thermal conductivity detector to allow the column effluent to bypass the filament when an undesired compound appears in the column effluent. The flow direction of the column effluent in the thermal conductivity detector is changed when the undesired compound disappears from the column effluent to allow the column effluent to pass through the filament. A thermal conductivity detector that allows the column effluent to (1) bypass the filament when an undesired compound appears in the column effluent and (2) pass through the filament when the undesired compound disappears in the column effluent is also described.

Abstract: A hydrogen sensor includes a hydrogen-absorbing material, a thermoelectric element, an electrical circuit for driving the thermoelectric element, a thermometer for the hydrogen-absorbing material, a temperature control circuit for maintaining the hydrogen-absorbing material at a constant temperature using the thermoelectric element, a unit for calculating the exothermic value of the hydrogen-absorbing material based on the electrical current flowing from the drive circuit, and a unit for calculating the hydrogen uptake of the hydrogen-absorbing material based on the exothermic value.

Abstract: A sensor module having a heating structure and a sensor element is described. The heating structure surrounds the sensor element so that heat dissipation through a frame is largely prevented. This yields a greater measuring accuracy of the sensor module. In particular, interfering influences due to a temperature dissipation through the mount frame are thereby prevented.

Abstract: In a calibration apparatus and method for a resistance thermometer a reference thermometer is located in thermal contact with a gas composition to generate, during a calibration period, a first reference temperature value for the gas composition at a first temperature, and an acoustic meter is located in acoustic contact with the gas composition and, during the calibration period, makes an acoustic velocity-related measurement for use in generating a second reference temperature value for the gas composition at a second temperature. A calibration unit coordinates the first and second reference temperature values with first and second measurement temperature values provided by the resistance thermometer at the first and the second temperatures, respectively, and establishes a calibration relationship therefrom.

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.

Abstract: A method and apparatus for determining the effective composition of a mixture of gases including a plurality of hydrocarbon gases, the method comprising selecting one or more effective hydrocarbons to represent the plurality of hydrocarbon gases in the gas mixture, the number of effective hydrocarbons being less than the number of hydrocarbon gases in the gas mixture whose composition is to be determined; measuring a number of characteristics of the gas mixture whose effective composition is to be determined, the number of characteristics to be measured being one less than the total number of components to be determined and determining the effective composition of the mixture of gases from the measurements of the characteristics of the gas mixture, a predetermined parameter dependent upon the characteristic measured and knowing that the sum of the components of the gas mixture equals 100%.

Abstract: A method of measuring the heat conductivity of an object to be measured, comprising generating heat between the object to be measured and a heat resistant material, causing heat to flow through the interior of the object to be measured and the interior of the heat resistant material and obtaining the heat conductivity of the object to be measured from a temperature difference between at least two points of the heat resistant material, a heat conductivity measuring instrument using the same and a method of producing a heat insulating material.