Abstract: A gas velocity and temperature sensor system comprising a first thermistor driven at a constant temperature and configured to output a flow signal representative of the power dissipated as a function of the gas velocity and a temperature signal representative of the temperature of the first thermistor, a second thermistor configured to output a gas temperature signal representative of the gas temperature proximate the second thermistor, and a processor responsive to the flow signal and the temperature signals, the processor configured to calculate gas velocity using an empirically derived equation in which gas flow velocity is function of a constant and the ratio of the power dissipated to the temperature difference between the temperature of the first thermistor and the gas temperature proximate the second thermistor, the processor deriving a signal representing the gas velocity.

Abstract: Sensor structure of a flow body protruding into a current for carrying out measurements of flow states, containing a structural part (1) with at least two measuring orifices (5), to which transfer lines (7) are coupled, which guide the flow medium from the measuring orifices (5) to a pressure converter system (13) for the purpose of determining the flow states. The outer shell (3) of the structural part (1) contains two areas (21, 22), which are arranged behind each other viewed in the direction of flow, wherein the first area (21) has greater thermal conductivity than the second area (22). Within the first area (21) heating elements (31) are arranged on the structural part (1), and are connected with a temperature control circuit with the temperature on the surface of the first area (21) as a control variable.

Abstract: A method and an apparatus for measuring the concentrations of the components of a fluid are described, which can be used to measure the concentrations of the components continuously in real time and to monitor a high pressure gas, and is suitably used for in-line monitoring. In the method and the apparatus, a fluid sample is conducted through a measuring tube, wherein the measuring tube has a small aperture with a constant diameter in a fluid flow path. The pressure difference (P1−P2) between the upstream and the downstream of the small aperture and the flow rate at the downstream of the small aperture are measured to determine the concentrations of the components of the fluid.

Abstract: A method and apparatus for measuring the flow velocity of a flowing fluid includes a positive temperature coefficient thermistor to be immersing within the flowing fluid in order to provide a measurement of the rate of heat dissipation of the thermistor produced by the flowing fluid, and thereby a measurement the flow velocity of the fluid. The positive temperature coefficient thermistor used has a resistance which increases sharply at the predetermined temperature at which electrical current is maintained in the thermistor such that the thermistor is self-controlled to maintain substantially the predetermined temperature, whereby the electrical current drawn by the thermistor is a measurement of the thermal load on the thermistor resulting from the thermal heat dissipation therefrom by the flowing fluid, and thereby a measurement of the flow velocity of the fluid.

Abstract: Disclosed here is a control unit employed for an internal combustion engine and provided with air flow sensor output correcting element capable of correcting a detected voltage error to occur in the air flow sensor according to a surge voltage and a supply voltage at each actuation of the thermal type air flow sensor. The thermal type air flow sensor output correcting element includes surge time measuring element for measuring a surge time in a value detected in the thermal type air flow sensor at the time of the sensor power on and supply voltage detecting means. The output correcting element thus calculates a warming-up characteristic correction amount for the thermal type air flow sensor according to the measured surge time and the detected supply voltage.

Abstract: A flowmeter which clamps around and seals to a pipe with probes projecting into the pipe through holes in the pipe, the useful separation of the probes being achieved by their entering the pipe through separate holes.

Abstract: A flow rate sensor capable of increasing a range where fluid flow rate can be detected with a high accuracy. The flow rate sensor includes: a sensor pipe; a resistor group; a reference resistor group; a constant current source; a first differential circuit; and a flow rate decision unit. The flow rate sensor further includes: a dummy sensor pipe where no fluid is flown; a dummy resistor group changing their resistance value according to the temperature and attached in the longitudinal direction, a dummy reference resistor group, a for-dummy constant current source, switch means for selectively connecting the resistor group with the dummy resistor group in series, a flow rate range increasing differential circuit for detecting a potential difference, and a third flow rate decision unit for obtaining the flow rate of the fluid flowing in the fluid passage according to the potential difference.

Abstract: The output characteristics of the sensing device or the control quantity of the sensing element can be adjusted by extracting an adjusting terminal in addition to a power source terminal, a ground terminal, an output terminal and the like outside a housing containing and protecting an electronic circuit. Further, by arranging the adjusting terminal inside a connector housing containing terminals such as the power source terminal, the ground terminal, the output terminal and the like, it is possible to prevent contact of foreign objects to the adjusting terminal and to water-proof the terminals for preventing corrosion since an associated connector is attached to the connector when the sensing device is actually used.

Abstract: Detection signals from an air flow meter which outputs detection signals different to each other for the forward flow and reverse flow of the intake air of an engine, are converted into intake air amount data of the same sign, and an offset amount is subtracted from the intake air amount data obtained by the conversion process, to obtain intake air amount date in which the forward flow and the reverse flow are distinguished from each other by positive and negative signs.

Abstract: A flow meter incorporating thermal loss sensors and an installation adapter to provide known flow conditions upstream of the meter. The installation adapter is in the form of a tubular extension projecting from a flange which in use is sandwiched between a pipeline flange and a flow meter flange. The flanges are configured such that a passageway defined by the adapter extension is located in a predetermined position relative to the flow meter. The flow meter may comprise a sensor array supporting at least three sensors which are not in alignment, one of those sensors being located centrally within the flow meter and the others being distributed at equal distances around the central position. In use, normal readings may be taken from a single one of the sensors, the other sensors being used for initial calibration and subsequent calibration test purposes only.

Abstract: To measure the flow in a liquid, the liquid (1) is led in a duct (2) along a flow sensor (3). The flow sensor (3) is integrated together with a processing and control circuit on a semiconductor substrate. It comprises a heating and, symmetrically thereto, two temperature sensors. The flow is determined from the temperature difference between the temperature sensors and/or from the power dissipation of the heating. For calibrating the sensor, a valve (4) is provided by means of which the duct (2) can be interrupted. This arrangement allows a flow measurement of high accuracy.

Abstract: An air temperature detector 12 is disposed close to an auxiliary passage sidewall 15, which has an auxiliary passage wall hole 9 formed near the air temperature detector 12. A heat-sensitive resistor 13 is also disposed close to the auxiliary passage sidewall 15, which has an auxiliary passage wall hole 10 formed near the heat-sensitive resistor 13. Further, a resistor heater 14 is disposed close to an auxiliary passage sidewall 16, which has an auxiliary passage wall hole 11 near the resistor heater 14.

Abstract: An outlet port in the upper end of a fluid flow passageway vertically formed in a flow rate measuring section (8) disposed in a fluid storage recess (23) communicating with a fluid inlet pipe through an opening (21a) communicates with a fluid outlet pipe (22) through an opening (22a). The heat type flow rate sensor (10) disposed in the flow rate measuring section (8) has a fin plate projecting into the fluid flow passageway through a sensor mount hole (8c). The flow rate measuring section (8) is formed with an auxiliary flow passageway for leading the fluid within the fluid storage recess (23) to the inlet port (811) in the lower end of the fluid flow passageway, the auxiliary flow passageway extending in parallel with the fluid flow passageway and having fluid introducing ports (822, 823, 824) and a fluid delivering port (821) leading to the fluid flow passageway.

Abstract: A system for measuring the velocity of a fluid can comprise a temperature sensor, for measuring the ambient temperature of the fluid, an RTD placed in the flow path of a fluid, the RTD being included as part of a Wheatstone bridge circuit, a digital potentiometer, the digital potentiometer also being included as part of a Wheatstone bridge circuit, and a controller coupled to the temperature sensor, the RTD and the digital potentiometer. In the system, the controller adjusts the digital potentiometer in response to an ambient fluid temperature signal from the temperature sensor such that the temperature of the RTD remains at a constant differential temperature above the ambient fluid temperature.

Abstract: Methods and apparatuses for temperature modification of a patient, or selected regions thereof, including an induced state of hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette of any one of several disclosed variations is attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within one of various described re-usable control units. The control units include a heater/cooler device, a user input device, and a processor connected to receive input from various sensors around the body and the system. The heater/cooler device may be thermoelectric to enable both heating and cooling based on polarity. A temperature control scheme for ramping the body temperature up or down without overshoot is provided.

Abstract: A flow sensor (1) is constituted by a substrate (4) having a front surface (4a) side facing a channel (3) for a measurement target fluid (2), and a channel forming member (5) and a plate (6) disposed oppositely across the substrate (4). The substrate (4) is formed of stainless steel having a thickness of about 50 &mgr;m to 150 &mgr;m into a plate. An electric insulating film is formed on that surface (4b) of the substrate (4) which is opposite to the channel (3) side, and a temperature detection sensor (7) for measuring the flow velocity (flow rate) of the fluid (2), an ambient temperature sensor (8), an electrode pad (9), and a thin metal film (10) for wiring are formed on it.

Abstract: A mass flow meter employs discrete chip-type temperature sensors to sense a fluid flow rate. The sensor can be a semiconductor chip such as SiC or silicon, or thin film tungsten on an AlN substrate. The sensors can be distributed symmetrically with respect to the conduit through which the fluid flows, and can be connected in a four-sensor bridge circuit for accurate flow rate monitoring. An output from the mass flow meter can be used to control the fluid flow.

Abstract: A heating resistor type air flow rate measuring apparatus is provided with a couple of heating resistors placed at the positions where those resistors may interfere thermally each other with respect to an air flow, and a couple of driving circuits for driving those heating resistors. The air flow rate signal is obtained by calculating the difference between the output signals of a couple of heating resistors in terms of heat radiation rate effected by an air flow, and adding the difference value onto the output signal of one of heating resistors.

Abstract: A method and apparatus for determining a state of zero gas flow in a conduit. A first gas flow signal has one polarity when gas flow is in one direction in the conduit and the opposite polarity when gas flow is in the opposite direction. A second gas flow signal has the same polarity for either direction of gas flow in the conduit. The derivatives of the first and second signals are taken at successive points in time to determine when the signs of the derivatives are present in a first predetermined combination of signs. A second point in time when the signs of the derivatives exhibit a second predetermined combination of signs different from the first combination is also determined. The combinations of signs are used to identify a state of zero gas flow in the conduit.

Abstract: In order to provide an intake flow rate detecting apparatus of an internal combustion engine which accurately compensates for an air flow meter detection error due to intake pulsation so as to make it possible to detect an intake flow rate more accurately, regardless of the of type of flow rate control mechanism, an intake flow rate detecting apparatus according to one embodiment of the invention includes a throttle valve which is provided in an intake passage and which adjusts a rate of the air that is taken into a combustion chamber of an internal combustion engine, at least one flow rate control mechanisms which are provided between the throttle valve and the combustion chamber and which control an air flow rate between the throttle valve and the combustion chamber, and a flow rate sensor which is provided upstream of the throttle valve in the intake passage and which detects a flow rate of air flowing through the intake passage.

Abstract: A high temperature anemometer includes a pair of substrates. One of the substrates has a plurality of electrodes on a facing surface, while the other of the substrates has a sensor cavity on a facing surface. A sensor is received in the sensor cavity, wherein the sensor has a plurality of bondpads, and wherein the bond pads contact the plurality of electrodes when the facing surfaces are mated with one another. The anemometer further includes a plurality of plug-in pins, wherein the substrate with the cavity has a plurality of trenches with each one receiving a plurality of plug-in pins. The plurality of plug-in pins contact the plurality of electrodes when the substrates are mated with one another. The sensor cavity is at an end of one of the substrates such that the sensor partially extends from the substrate. The sensor and the substrates are preferably made of silicon carbide.

Abstract: The output characteristics of the sensing device or the control quantity of the sensing element can be adjusted by extracting an adjusting terminal in addition to a power source terminal, a ground terminal, an output terminal and the like outside a housing containing and protecting an electronic circuit. Further, by arranging the adjusting terminal inside a connector housing containing terminals such as the power source terminal, the ground terminal, the output terminal and the like, it is possible to prevent contact of foreign objects to the adjusting terminal and to water-proof the terminals for preventing corrosion since an associated connector is attached to the connector when the sensing device is actually used.

Abstract: A method and a system are disclosed for identifying a gas type. The system includes a first sensor in contact with the gas and which produces a first electrical output signal indicative of a first condition of the gas. Similarly, a second sensor is also in contact with the gas and produces a second electrical output signal indicative of a second condition of the gas. A processor receives the output signals as input signals from the first and second sensors and determines the type of gas by calculation or from lookup tables stored in memory accessible to the processor. The first and second conditions of the gas are selected from the group of temperature, mass flow rate, temperature and pressure.

Abstract: A flow sensor, which can detect flow velocity in a wide range including high flow velocity area with simple structure. A flow sensor includes a substrate having a hollow portion; and a thin film structure portion provided above the hollow portion. The thin film structure portion is provided with a heater formed in a center portion, an upper and a lower stream temperature detectors for detecting temperature of the fluid, a fluid thermometer for detecting temperature of the fluid, and thermal couple films provided on the substrate at a portion, where is between the heater and both temperature detectors. According to this structure, the thermal couple films enhance thermal coupling between the heater and the temperature detectors.

Abstract: The present invention relates to a method of calculating the pressure drops created by a given fluid in a circuit having a determined thermal profile. The method includes making up a database (BD) giving the rheology of various fluids at least according to the temperature; segmenting a thermal profile (2, 3) into sections (4, 5, 6, 7) and determining a representative temperature value (T1, T2, T3, T4) for the fluid in each section; using the database for determining the rheology of the fluid in each section at the representative temperature; and calculating and adding up the pressure drops in each section considering the rheology determined.

Abstract: A circuit board, which includes one or more sensors, is integrated in a fluid control device, such as a valve manifold and a base plate. The fluid control device selectively directs a fluid used to control pneumatic or hydraulic equipment. The sensors are used to measure physical characteristics of the fluid, such as flow rate, pressure, and temperature.

Abstract: The present invention relates to an apparatus and method for measuring the volume of a flowing media. The apparatus includes a pulse sensor and a temperature sensor wherein the temperature sensor and the pulse sensor are utilized to provide data for calculating the volume of the flowing media.

Abstract: The invention concerns a mass flow meter comprising at least a resistive wire (1 or 2) placed in the path of a fluid whereof the flow rate is to be measured, means (30) for applying to the wire current pulses, measuring means for determining the cooling speed of the wire between said pulses. The invention is characterised in that it comprises means for determining, on the basis of at least one measurement of the cooling speed, the type of fluid on the path of which the resistive wire is arranged.

Abstract: A gas flow determination method and a corresponding gas flow determination device are described.

Abstract: A gas mass flow meter includes an elongated channel extending through a high thermal mass body and a critical flow nozzle in a downstream portion of the channel. A heat exchanger is provided upstream in the channel. Gas is forced through the heat exchanger and the critical flow nozzle at a flow rate of up to 5000 slm and at sufficiently high-pressure to ensure critical flow of the gas through the critical flow nozzle. The heat exchanger brings the gas close to the temperature of the high thermal mass body. The pressure of the gas is measured upstream and downstream from the nozzle and the temperature of the gas emerging from the heat exchanger is measured. The mass flow rate of gas through critical flow nozzle is computed from the upstream pressure, downstream pressure, temperature of the high thermal mass body, density of the gas, and a dimensional characteristic of the critical flow nozzle.

Abstract: A flowmeter which clamps around and seals to a pipe with probes projecting into the pipe through holes in the pipe, the useful separation of the probes being achieved by their entering the pipe through separate holes.

Abstract: To offer a mass airflow measuring apparatus in which the effect of the adhesion onto the heating resistor caused while the engine is off is reduced and the measuring accuracy is improved. The apparatus measures the mass airflow of the air sucked into the internal combustion engine, using the heating resistor 1. The power control circuit 4 maintains the heating resistor 1 temperature equal to or higher than the temperature during the operation of the internal combustion engine after the internal combustion engine has stopped and until the temperature of the internal combustion engine and its apparatuses installed in the suction system has lowered below the generation temperature of volatile gas such as oil vapor.

Abstract: A compact, one-part respiratory flow sensor with a small dead space volume for the simultaneous measurement of both the gas volume flow and the concentration of gas components of the respiratory flow. The respiratory flow sensor has a tubular housing (1) with two opposite windows (2, 3) which are arranged at right angles to the direction of flow and limit the respiratory flow and are formed of a material transparent to infrared radiation. An infrared sensor with an infrared radiation source (4) and with at least one infrared radiation detector (5) is connected to the housing (1). The infrared radiation source (4) irradiates one of the two windows (2, 3) of the housing (1). The infrared radiation detector (5), of which there is at least one, receives the infrared radiation of the infrared radiation source (4) after its passage through the respiratory flow and the two windows (2, 3) limiting the respiratory flow.

Abstract: A system for detecting the level of fluid in a fluid containing vessel. The system includes a device for applying energy to a selected location on the vessel. A sensor in proximity to the location detects the energy level at the location during first and second intervals. A memory device stores data representative of the energy detected by the sensor at each interval, and a logic circuit compares the amount of energy of the first interval to that of the second. Data corresponding to the level of fluid in the vessel may be displayed locally or signaled to remote data receiving and display devices, as appropriate.

Abstract: The present invention discloses a mass flow sensor and a measuring apparatus, and more particularly, to a mass flow sensor comprising a structure that mounts and/or houses a hybrid ceramics having a combined construction including a boundary 4 dividing a static temperature coefficient thermistor 2 and, as an insulator, a supporting body 3; with electrodes 5 and 5′ and the insulation coating and thermal conductive metal, characterized in that it electrically insulates outer side of the thermistor 2 with the supporting body 3 in order to equip the resister thermistor having greater static temperature coefficient than existing platinum or nickel elements while self-limited exothermic temperature within the conduit 11, enables the temperature sensor and mass flow sensor to directly detect fluid inside of the conduit to achieve speedy detection and accurate measurement of flow, and to minimize heat loss from terminal portions and to solve decrease of sensing capability of sensor caused from latent heat of th

Abstract: A thermal flow-rate sensor has a flow sensor (3) and a thermal-conductivity measuring cell (4). The flow sensor (3) comprises a first heating device and a first temperature detector, which reacts to the temperature of the first heating device, and can be exposed to a flowing fluid whose flow rate is to be determined. The thermal-conductivity measuring cell (4) comprises a measuring-cell casing (42), a second heating device and a second temperature detector which reacts to the temperature of the second heating device. The measuring-cell casing (42) has at least one opening (46) arranged for entry of the fluid into the measuring-cell casing (42).

Abstract: A method and apparatus for providing an indication of the composition of an examined fluid by using an electrical resistor, particularly a positive temperature coefficient thermistor, for measuring the thermal conductivity of the examined fluid with the known thermal conductivity of different fluid compositions. The method and apparatus are particularly described for indicating the relative proportions of a working fluid in the liquid and vapor phases in one or more stages of a heat pump. Another described application is for indicating the liquid level in a liquid vaporizer.

Abstract: A pressure regulating device with the wetted surfaces and a sensing element operated by a reference control pressure made for control and regulation of highly corrosive fluids. It includes a body member having an inlet and an outlet passageway separated from one another by the engagement of a tongue and groove seal joint of a sensing element and a controlling element assembled on to the body. Applying a reference control pressure to the top side of the sensing element disengages the seal joint which allows fluid at high pressure to flow into the outlet passageway and under the sensing element opposite to the reference control pressure side. Once force produced by pressure under sensing element equals to the force produced by reference control pressure on top of the sensing element, the seal joint closes to prevent further flow.

Abstract: A thermowell assembly (20) shown in FIG. 2 is positioned in a pipeline (10) for sensing the temperature of the fluid medium in the pipeline (10) for transmitting the sensed temperature to a meter (12). A temperature sensing probe is received within a temperature conducting tube (36) forming a thermowell and having a plurality of annular fins (40) extending thereabout. In the embodiments of FIGS. 1-7, a liquid (50) is provided in an annular space between the thermocouple (28) and the temperature conducting tube (36). Non-metallic members (70, 74, 80) are positioned between the pipeline (10) and the temperature transmitting tube (36) to isolate thermocouple (28) from ambient changes in the temperature of metal pipeline (10) which may result in an error in the temperature of the flow medium sensed by the thermowell assembly (20). High temperature embodiments shown in FIGS.

Abstract: The process for the construction of a micro-thermocouple sensor designed to be incorporated in a mass flow meter for the circulation of gaseous fluids, including of the following steps:

Abstract: A flow regulation control valve for regulating volume flows in pipelines including valve housing with a flow chamber, a control or shut-off member arranged in the flow chamber for setting a desired flow state through the valve, at least one sensor arranged in the vicinity of the flow chamber of the valve housing for sensing a characteristic value of the flow through the flow chamber, an electronic data store or memory for storing specific characteristic values of the housing of the flow regulation control valve, and an evaluation unit which is connected to the sensor and determines the volume flow from the values measured by the sensor with reference to the characteristic values of the valve stored in the data store.

Abstract: A compact, one-part respiratory flow sensor with a small dead space volume for the simultaneous measurement of both the gas volume flow and the concentration of gas components of the respiratory flow. The respiratory flow sensor has a tubular housing (1) with two opposite windows (2, 3) which are arranged at right angles to the direction of flow and limit the respiratory flow and are formed f a material transparent to infrared radiation. An infrared sensor with an infrared radiation source (4) and with at least one infrared radiation detector (5) is connected to the housing (1). The infrared radiation source (4) irradiates one of the two windows (2, 3) of the housing (1). The infrared radiation detector (5), of which there is at least one, receives the infrared radiation of the infrared radiation source (4) after its passage through the respiratory flow and the two windows (2, 3) limiting the respiratory flow.

Abstract: A system for sensing or measuring the motion of a fluid such as air. The system typically has a two-part plastic body containing an internal flow passage. The parts of the body may snap together or attach with an adhesive. A transducer or an electronic sensor is typically located within the flow passage, which may measure mass flow rate and may have two resistive thermal devices (RTDs) located on either side of a heat source. The body may have two elongated port tubes configured to attach to tubing. The port tubes may contain venturis, and may be substantially straight and substantially parallel, forming a U shape. A metal lead frame may be provided in electrical communication with the sensor. The lead frame may be integrally molded within the body, and may have a lower coefficient of thermal expansion than the body. The internal flow passage and the sensor may be substantially symmetrical and measure the flow rate of the fluid substantially equally in either flow direction.

Abstract: A liquid flow microsensor having a flow tube with a sensor aperture on the surface and having a straight-through conduit for fluid flow. A sensor assembly is mounted within the sensor aperture, and includes a thermal sensor positioned to be within the straight-through conduit in direct communication with the fluid flow so as to sense thermal characteristics representative of a fluid flow rate.

Abstract: An air flow measuring apparatus, is of a type converting digital values Vadc having a non-linearity characteristic to a flow rate in air flow rate conversion processing. The apparatus, is provided with voltage output conversion processing, uses a QV map formed on a PROM, and is formed so as to obtain a voltage output signal Vout having a property equivalent to a signal Vin outputted from a sensor circuit by converting a smoothed signal Qaf into a voltage value having a non-linearity characteristic.

Abstract: A thermowell assembly (20) shown in FIG. 2 is positioned in a pipeline (10) for sensing the temperature of the fluid medium in the pipeline (10) for transmitting the sensed temperature to a meter (12). A temperature sensing probe is received within a temperature conducting tube (36) forming a thermowell and having a plurality of annular fins (40) extending thereabout. In the embodiments of FIGS. 1-7, a liquid (50) is provided in an annular space between the thermocouple (28) and the temperature conducting tube (36). Non-metallic members (70, 74, 80) are positioned between the pipeline (10) and the temperature transmitting tube (36) to isolate thermocouple (28) from ambient changes in the temperature of metal pipeline (10) which may result in an error in the temperature of the flow medium sensed by the thermowell assembly (20). High temperature embodiments shown in FIGS.

Abstract: A thermowell assembly (20) shown in FIG. 2 is positioned in a pipeline (10) for sensing the temperature of the fluid medium in the pipeline (10) for transmitting the sensed temperature to a meter (12). A temperature sensing probe is received within a temperature conducting tube (36) forming a thermowell and having a plurality of annular fins (40) extending thereabout. In the embodiments of FIGS. 1-7, a liquid (50) is provided in an annular space between the thermocouple (28) and the temperature conducting tube (36). Non-metallic members (70, 28, 80) are positioned between the pipeline (10) and the temperature transmitting tube (36) to isolate thermocouple (28) from ambient changes in the temperature of metal pipeline (10) which may result in an error in the temperature of the flow medium sensed by the thermowell assembly (20). High temperature embodiments shown in FIGS.

Abstract: A thermal flow-rate sensor has a flow sensor (3) and a thermal-conductivity measuring cell (4). The flow sensor (3) comprises a first heating device and a first temperature detector, which reacts to the temperature of the first heating device, and can be exposed to a flowing fluid whose flow rate is to be determined. The thermal-conductivity measuring cell (4) comprises a measuring-cell casing (42), a second heating device and a second temperature detector which reacts to the temperature of the second heating device. The measuring-cell casing (42) has at least one opening (46) arranged for entry of the fluid into the measuring-cell casing (42).

Abstract: A gas sensing element comprises a solid electrolytic element, a measured gas sensing electrode provided on an outer surface of the solid electrolytic element, and a reference gas sensing electrode facing a reference gas chamber. A heater is accommodated in the reference gas chamber. A contact portion is provided on an outer cylindrical surface of the heater so that the contact portion is brought into contact with an inside surface of the solid electrolytic element defining the reference gas chamber. A heating peak position of the heater is in the vicinity of the contact portion.

Abstract: The invention relates to a measuring arrangement for measuring the flow velocity of a gas. With a single measuring sensor, a physical quantity of the gas as well as the gas temperature can be measured. During a first measuring phase in which the measuring sensor is heated to an operating temperature by a heating current, a first measurement quantity is determined from the change of the heating current caused by the physical quantity. During a second measuring phase, the measuring sensor is connected to a resistance measuring device and the heating current of the measuring sensor is reduced in such a manner that the inherent warming of the measuring sensor is small compared to the operating temperature. A second measurement quantity is determined from the resistance of the measuring sensor which is proportional to the temperature of the gas.