Abstract: Techniques for the design and operation of an efficient battery-powered meter are described herein. A metrology unit of the meter may be at least partially located in the gas flow of a pipe, and measures gas flow rate data according to a static flow sensor. The metrology unit calculates raw gas-volume data using at least the flow rate data as input. The metrology unit measures gas temperature to produce gas temperature data, and adjusts the raw gas-volume data, based at least in part on the gas temperature data, to produce corrected gas-volume data. The metrology unit accumulates the corrected gas-volume data over multiple minutes, hours or even days, and then sends the accumulated corrected gas-volume data to an index unit of the meter. By accumulating the data over time, fewer data transmissions are required. The index unit may send the accumulated the accumulated corrected gas-volume data to a utility server.

Abstract: A mass flow controller (10) comprises a fluid inlet (15) and at least one first flow meter (11) to measure a first flow rate (F1) and to output a first flow signal (FS1); at least one second flow meter (12) to measure a second flow (F2) rate and to output a second flow signal (FS2); a control device (13) connected to said first and second flow meters (11,12) and configured and arranged to generate a control signal (C); and at least one control valve (14) connected to said control device (13) to control a total flow rate (Fout) through the mass flow controller (10) in response to the control signal (C). The control signal (C) is generated as a function of both the first and second flow signals (FS1,FS2) such that the mass flow controller's (10) sensitivity to perturbations of said inlet pressure is minimized.

Abstract: A bimetallic nanowire synthesis method is provided. The method includes adding first and second solutions into a vessel containing a porous template with the first solution containing first and second reagents added on one side of the porous template and the second solution added on an opposite side of the porous template. The first reagent includes a first salt of at least one of a transition metal, an actinide metal and a lanthanide metal. The second reagent includes a second salt of at least one of a transition metal, an actinide metal and a lanthanide metal. The second solution contains a reducing agent.

Abstract: An information handling system (IHS) cooling system includes a multi-IHS chassis having at least one fan system that produces an airflow. An IHS is positioned in the multi-IHS chassis. The IHS includes an IHS chassis that houses a processing system and a memory system. An airflow channel is defined within the IHS chassis and is configured to receive at least a portion of the airflow produced by the at least one fan system. An airflow impedance element is positioned in the airflow channel, and includes a first orientation in which the airflow impedance element extends into the airflow channel to impede airflow through the airflow channel. The airflow impedance element is configured to change shape as a function of temperature into at least one second orientation that reduces the impedance of airflow through the airflow channel. In some embodiments, the airflow impedance element is a bimetallic plate.

Abstract: A surface acoustic wave (SAW) device comprising at least one heating element formed on the substrate; at least one temperature sensor having a first electric component on the substrate whose resistance varies with the temperature of the substrate and a second electric component whose resistance does not vary; and a temperature controller including an operational amplifier bonded in thermally conductive relationship to the substrate. The operational amplifier is responsive to the output of the temperature sensor to apply power to the heating element and thereby maintain the temperature of the substrate within a predetermined temperature range. The transducer, heating element, and first component are monolithically formed on the substrate, and only three electrical connections are on the substrate at voltage to off-SAW die points.

Abstract: A method for determining mass flow of a gas by means of a mass flow meter, which has a first and a second temperature sensor, which can be flowed around by the gas. The first temperature sensor is heated with a heating power Q, wherein the mass flow of the medium is determined by means of a power coefficient PC=Q/?T as a function of a heating power Q and a temperature difference ?Tm=T1?T2 between the measured values of the temperature sensor. A corrected power coefficient PCcorr is determined, wherein at least one correction occurs by means of at least one recovery correction term Ki, wherein the recovery correction term Ki has the form Ki=?x·u2/(2·cp), wherein u is the flow velocity and cp the heat capacity of the medium, ?x is an element of the set {?1; ?2; ?12}, ?1:=e1?cr, ?2:=e2?cr and ?12:=e1?e2=?1??2, e1 and e2 are the recovery factors of the first, respectively second, temperature sensors, and wherein cr is a constant reference value, for which holds cr?1, especially cr=1.

Abstract: A gas flow sensing device, and related method of manufacturing, comprising a conductive layer encapsulated in dielectric film, suspended over a cavity to form a diaphragm. The conductive layer functions as both a heating a sensing element and is patterned to provide uniform heat distribution across the diaphragm. The device is designed to sense flow from any direction relative to the device and the design of the dielectric film and diaphragm reduces sensor drift during prolonged operation.

Abstract: A highly reliable, simple-structured and low-cost thermal flowmeter is provided. The thermal flowmeter in an embodiment according to the present invention includes a planar heating element located to surround a part of an outer side surface of a flow path; first and second temperature detection elements located on the planar heating element at a prescribed interval; and electrodes located at both of two ends of the planar heating element. The planar heating element contains a carbon material and cellulose fiber.

Abstract: The present invention provides a thermal conductivity detector capable of realizing high detection performance even with the use of a miniaturized heating element, and expanding an effective applicable temperature range of a heating element, and to provide a gas chromatograph using the same. The thermal conductivity detector comprises a flow-path through which a measurement gas is caused to flow, a heating element disposed inside the flow-path, the heating element being formed on the substrate, for detecting thermal conductivity of the measurement gas according to magnitude of an amount of heat taken away from the heating element by the measurement gas, wherein said heating element is provided with a beam including a part where the beam is folded at a predetermined angle, the part being formed at the central part of the beam.

Abstract: An air-flow sensor is configured to be positioned in an air-flow and attached to a surface in a manner that allows air to flow over an extremity of the sensor. The air-flow sensor includes a base plate, a first heater, a first temperature sensor, a spacer, a second heater, a second temperature sensor, and a cap. The base plate is configured to be the coupled to the surface. The first heater is positioned on the base plate and is configured to heat the base plate. The first temperature sensor is positioned to measure a first temperature of the first heater. The spacer is positioned on the first heater and the second heater is positioned on the spacer. The second temperature sensor is positioned to measure a second temperature of the second heater. The cap is positioned on the second heater, which is configured to heat the cap.

Abstract: A method for determining flow in a medium, comprising applying thermal energy to at least one probe of a pair of probes, the probes configured for placement in the medium and varying the applied thermal energy of the at least one probe to maintain a constant temperature differential between the pair of probes and determining a flow from the applied thermal energy while maintaining the constant temperature differential.

Abstract: The invention relates to a sensor (102) and a control unit (702) for cooperation with the sensor. The sensor (102) serves for measuring a velocity of a fluid (308) flowing through a channel (306). The sensor (102) employs a thermal measuring principle, which measuring principle is robust regarding disturbances on the amount of power dissipated by the heating element (106). A sensor receiver (110) is arranged for receiving an electromagnetic radiation generated by a control transmitter (722) comprised in a control (702) unit for cooperation with the sensor (102). The electromagnetic radiation is employed for powering the heating element (106) which is arranged for heating the fluid. On the basis of a measurement signal generated by a transducer arrangement comprised in the sensor (102), a control actuator (724) controls the velocity of the fluid. For this purpose a sensor transmitter (116) is arranged for transmitting the measurement signal to a control receiver (734).

Abstract: UV-C light assembly is designed to kill germs (bacteria, molds, protozoa, virus, and yeast) in the forced airstreams of HVAC systems, thus preventing the spreading of germs into other rooms or spaces. An air-flow activated switch is invented for turning on the UV-C lights when airstreams pass through and turning off when airstreams stop in the HVAC systems. The UV-C light assembly is installed inside duct through air filter's opening. The UV-C germicidal assembly is an easy add-on to an existing HVAC system for indoor air purification. The UV-C light sources are either LEDs or fluorescent tubes.

Abstract: An air flow rate measuring apparatus includes a heater and a control circuit. The heater heats a part of an intake air sucked into an engine. The control circuit controls an energization of the heater. The heater has a measuring-mode temperature when a flow rate of the intake air is measured. The control circuit has a heat cleaner which temporarily raises a temperature of the heater higher than the measuring-mode temperature when an energization of the air flow rate measuring apparatus is started.

Abstract: A vacuum-cavity-insulated flow sensor and related fabrication method are described. The sensor comprises a porous silicon wall with numerous vacuum-pores which is created in a silicon substrate, a porous silicon membrane with numerous vacuum-pores which is surrounded and supported by the porous silicon wall, and a cavity with a vacuum-space which is disposed beneath the porous silicon membrane and surrounded by the porous silicon wall. The fabrication method includes porous silicon formation and silicon polishing in HF solution.

Abstract: A thermal flow sensor is responsive only to a modulated component of the flow. At zero flow the modulated component disappears, except for an artifact caused by motion of the modulator. This artifact is minimized by reducing the extent of modulator motion and by sampling the modulated signal at a quiescent part of the modulator's operating cycle. This results in a thermal flow sensor with a very stable zero.

Abstract: Sap flow sensor apparatus and concomitant methodology for determining the sap flow within plant stems of herbaceous plants and trees using a simplified Stem Heat Balance methodology. Optimum irrigation and utilization of beneficial plant health statistics are enabled using a sap flow sensor apparatus configured with a flexible, sealed sensor layer and multi-layered insulation including an elastic hook-and-loop attachment for enclosing the flexible, sealed sensor layer, soft-foam insulation, a waterproof membrane cloth permeable to water vapor and impermeable to water drops, and an outermost reflective barrier. Based upon the calculations derived from the simplified Stem Heat Balance formula, embodiments afford operational and economic efficiencies due to reduction of the prerequisite electronics to a 1-Channel dT signal.

Abstract: A sensor arrangement including a probe and a bracket that are provided for a calorimetric mass flow meter for measuring the mass flow in a measuring tube. The probe is mounted in the bracket in such a manner that the probe is guided essentially without contact with a radial spacing through a probe recess a wall of the measuring tube and is positioned in a cross section of a flow-through area of the flow of the measuring tube. The bracket is designed in such a manner that the probe is thermally de-coupled from the measuring tube. The sensor arrangement for the calorimetric mass flow meter is capable of increasing the measuring accuracy and increasing the flexibility during operation.

Abstract: The present invention significantly modifies “The Overflow Process”. It includes a method and apparatus for measuring glass flow rate and maintaining a constant glass flow rate. It also embodies design features and methods that support and stress the forming apparatus in a manner such that the deformation that results from thermal creep is corrected, thus minimizing the effect of the thermal creep on the thickness variation of the glass sheet. The present invention also embodies design features that change the process from a single step (combined flow distribution and cooling) to a two step process; step one being flow distribution and step two being cooling.

Abstract: A system includes a controller configured to receive a signal from a thermal radiation sensor indicative of a temperature of a region including at least one fluid passage. The controller is also configured to detect a leak within the at least one fluid passage based on the signal.

Abstract: Apparatus and methods are disclosed to measure airflow within a chassis-cooling pathway of an appliance. The rate of airflow is determined based on the differential heating among a pair of sensor devices, such as thermistors, transistors, diodes or resistive thermal devices operating at distinctly different power levels. The appliance utilizes the calculated airflow rate to perform safety-related tasks, such as de-energizing heating elements when low or no airflow is detected.

Abstract: One aspect of the invention provides a flow sensing apparatus for sensing fluid flow in a nano-scale high-performance liquid chromatography apparatus. The flow sensing apparatus includes: a fluid channel that allows a fluid to flow in a first direction; a first infrared sensor arranged at a first position along the fluid channel such that it senses a temperature of the fluid; a second infrared sensor arranged at a second position along the fluid channel and separated from the first sensor by a predetermined distance along the fluid channel; and a heating element arranged between the first and second infrared sensors. The heating element is equally spaced from the first and second infrared sensors.

Abstract: A heat conduction-type sensor corrects (calibrate) effects of a temperature of a measurement target fluid and a type of the fluid on a measurement value in measurement of a flow velocity, a mass flow, or an atmospheric pressure. Also provided is a thermal flow sensor and a thermal barometric sensor with this correcting function, high sensitivity, simple configuration, and low cost. At least two thin films that are thermally separated from a substrate through the same cavity are provided, one thin film comprises a heater and a temperature sensor, and the other thin film comprises at least one temperature sensor, the temperature sensors being thin-film thermocouples. The thin film is arranged in proximity so that it is heated only through the measurement target fluid by heating of the heater. A calibration circuit calculates and compares quantities concerning heat transfer coefficients of a standard fluid and the unknown measurement target fluid.

Abstract: A sensor having a sensor bridge supported above a substrate is disclosed. A number of thermally isolating apertures are provided in the sensor bridge to help increase the thermal isolation of the sensor bridge from the substrate. In one illustrative embodiment, a heater element, an upstream sensor element, and/or a downstream sensor element are provided on the sensor bridge. A plurality of apertures may extend through the sensor bridge to thermally isolate the heater element, the upstream and/or downstream sensor element from the substrate and/or from each other. In one illustrative embodiment, the plurality of apertures may be provided at spaced locations adjacent a first lateral side of the sensor bridge, adjacent the second lateral side of the sensor bridge, between the heater element and the upstream sensor element, and/or between the heater element and the downstream sensor element. In some cases, the plurality of apertures may be substantially round, oval, rectangular and/or any other suitable shape.

Abstract: An apparatus for determining and/or monitoring mass flow of a fluid medium through a pipeline, or through a measuring tube. The apparatus includes two temperature sensors and a control/evaluation unit. The two temperature sensors are arranged in a region of a housing facing the medium and in thermal contact with the medium flowing through the pipeline, or through the measuring tube. A first of the temperature sensors is heatably embodied. A second of the temperature sensors provides information concerning the present temperature of the medium. The control/evaluation unit, on the basis of primary measured variables, such as temperature difference between the two temperature sensors and/or heating power fed to the first temperature sensor, ascertains the mass flow of the medium through the pipeline.

Abstract: The invention relates to a sensor system (102) for measuring a velocity of a fluid (110) flowing through a channel (108), comprising a heating element (104) for heating the fluid, wherein the heating element (104) is provided with a predetermined level of power during operation. The sensor system (102) furthermore comprises a primary electronic circuit (114) having a primary resonance frequency, which primary resonance frequency is temperature dependent. Herein the temperature of the primary electronic circuit (114) is determined by heat transferred from the heating element (104) to the fluid (110) flowing through the channel (108). In addition, the sensor system (102) comprises a transducer arrangement (126) configured for generating a measurement signal (128) indicative for the velocity of the fluid (110) flowing through the channel (108). Herein, the measurement signal (108) is based on the primary resonance frequency.

Abstract: Flow sensor assemblies having increased flow range capabilities are disclosed. In one illustrative embodiment, a flow sensor assembly includes a housing with an inlet flow port, an outlet flow port, and a fluid channel extending between the inlet flow port and the outlet flow port. One or more partitions are provided in the fluid channel of the housing to define two or more fluid sub-passages. A flow sensor, for sensing a measure related to a flow rate of a fluid flowing through the fluid channel, is positioned in one of the two or more fluid sub-passages. In some cases, the cross-sectional area of each of the two or more fluid sub-passages may be substantially the same, but this is not required. The housing may be formed from a single molded part defining the inlet and outlet flow ports, at least a portion of the fluid channel, and one or more of the partitions. In this case, a top cover may be provided and mounted to the housing to define the remaining portion of the fluid channel, if desired.

Abstract: A device for characterizing the nature of an aerodynamic stream along a wall, the device including multiple temperature-sensitive optical nodes of Bragg grating type distributed along an optical fiber, and means for determining the variations in speed of the aerodynamic stream. The nodes are distributed along a fiber placed substantially following the route of a streamline, and processing means are devised so as to differentiate the temporal and spatial characteristics of the signals of thermal flowrate among the nodes.

Abstract: A sensor having a sensor bridge supported above a substrate is disclosed. A number of thermally isolating apertures are provided in the sensor bridge to help increase the thermal isolation of the sensor bridge from the substrate. In one illustrative embodiment, a heater element, an upstream sensor element, and/or a downstream sensor element are provided on the sensor bridge. A plurality of apertures may extend through the sensor bridge to thermally isolate the heater element, the upstream and/or downstream sensor element from the substrate and/or from each other. In one illustrative embodiment, the plurality of apertures may be provided at spaced locations adjacent a first lateral side of the sensor bridge, adjacent the second lateral side of the sensor bridge, between the heater element and the upstream sensor element, and/or between the heater element and the downstream sensor element. In some cases, the plurality of apertures may be substantially round, oval, rectangular and/or any other suitable shape.

Abstract: A method for determining and/or monitoring aggregate state changes on a thermal, flow measuring device of at least a first part of a measured medium, wherein, as a result of the temperature of the medium being measured, as a result means of the chemical composition of the medium being measured and as a result of the partial pressure of the at least first part of the medium being measured and/or as a result of the total pressure of the medium being measured, at least one phase boundary line of the at least first part of the medium being measured is ascertained.

Abstract: A thermal flow sensor integrated circuit for sensing flow in a channel based on temperature measurements, the integrated circuit having a temperature sensing element (30) on a front side of the integrated circuit arranged to face the channel, and a bond pad (60, 200) coupled electrically to the temperature sensing element, for making electrical contact off the integrated circuit, the bond pad being arranged to face away from the channel. By having the bond pad facing away from the channel, the space needed for the bond pad and any connections to it need not extend beyond the temperature sensing element and get in the way of the channel. Hence the temperature sensing element can be located closer to the channel or in the channel to enable measurements with better response time and sensitivity.

Abstract: A flow sensor may be formed by bonding a sensor chip formed with a flow rate detecting part and a flow path-forming member that is provided on the sensor chip and is formed with a flow path for a fluid flowing in the flow rate detecting part to each other on the upper surface of a substrate. The flow path-forming member may be formed by bonding a transparent first flow path forming member and a second flow path-forming member to each other. The first flow path forming member has a plate shape, and is provided with an inflow port and a outflow port for the fluid to be measured, and the second flow path forming member has a plate shape, and is provided with a through hole that forms the flow path along the flow of the fluid flowing along the flow rate detecting part.

Abstract: A detector for identifying a fluid is disclosed. The detector comprises a probe having a thermistor, the probe being arranged to be exposed to a fluid and to allow thermal flow between the fluid and the thermistor; a temperature sensor to measure the ambient temperature of the fluid and a controller. The controller is arranged to supply electrical power to the thermistor and to provide an output indicative of the identity of the fluid based upon whether the electrical power supplied to the thermistor is above or below a threshold value. The threshold value is adjustable in accordance with the measured ambient temperature of the fluid. Examples of such a detector provide reliable fluid identification despite variations in ambient temperature of the fluid and such a detector may be compact, inexpensive, reliable and robust.

Abstract: Provided is a compact apparatus for measuring the flow rate of a fluid. The apparatus includes a heated measure element and a heated reference element which are in substantially the same thermal environment within a measure cell, except that the measure element is situated in the path of the cooling fluid flow and the reference element is sheltered from this direct fluid flow. These elements are arranged as parallel and concentric planar elements that are essentially identical to each other with matching thermal characteristics. The elements are electrically connected in a Wheatstone bridge arrangement. Thermal exchange between the reference and measure elements is used to optimise noise rejection due to common mode background thermal effects. Measured parameters from the bridge can be used to derive the fluid flow rate.

Abstract: A sensor arrangement including a probe and a bracket that are provided for a calorimetric mass flow meter for measuring the mass flow in a measuring tube. The probe is mounted in the bracket in such a manner that the probe is guided essentially without contact with a radial spacing through a probe recess a wall of the measuring tube and is positioned in a cross section of a flow-through area of the flow of the measuring tube. The bracket is designed in such a manner that the probe is thermally de-coupled from the measuring tube. The sensor arrangement for the calorimetric mass flow meter is capable of increasing the measuring accuracy and increasing the flexibility during operation.

Abstract: The present disclosure relates generally to flow sensors, and more particularly, to methods and devices for reducing variations in fluid flow across the flow sensor for increased accuracy and/or reliability. In one illustrative embodiment, a flow sensor assembly includes a housing with an inlet flow port and an outlet flow port. The housing defines a fluid channel extending between the inlet flow port and the outlet flow port, with a flow sensor positioned in the housing and exposed to the fluid channel. The flow sensor is configured to sense a measure related to the flow rate of a fluid flowing through the fluid channel. A porous insert is situated in the fluid channel, sometimes upstream of the flow sensor. When so configured, and during operation of the flow sensor assembly, a fluid may pass through the inlet flow port, through the porous insert, across the flow sensor, and through the outlet flow port.

Abstract: The invention concerns the production of segmented nanowires and components having said segmented nanowires. For the production of the nanowire structural element, a template based process is used preferably, wherein the electrochemical deposition of the nanowires in nanopores is carried out. In this manner, numerous nanowires are created in the template foil. For the electrochemical deposition of the nanowires, a reversed pulse procedure with an alternating sequence consisting of cathodic deposition pulses and anodic counter-pulses is carried out. By this means, segmented nanowires can be produced.

Abstract: A constant temperature anemometer is disclosed. The anemometer includes electrically conductive pins including a first set of pins and a second set of pins. A conductor is coupled to the electrically coupled pins. A current source is configured to provide a current through the conductor between the first set of pins. A voltage sensor is configured to measure the voltage across the conductor between the second set of pins. The current source and voltage sensor are configured to maintain a constant resistance of the conductor between the first set of pins.

Abstract: One embodiment of the present invention involves a thermal sensor and a method of using the same. One thermal sensor is adapted to output a signal which is unaffected by external longitudinal and orthogonal thermal gradients. In one embodiment, the mass flow controller thermal sensor comprises a capillary tube having an upstream tube portion, a tube bend portion, and a downstream tube portion, the downstream portion being substantially parallel to the upstream portion. A distance between the upstream tube portion and the downstream tube portion in one embodiment is no greater than half the upstream portion and downstream portion lengths, a first pair of thermal sensing elements are coupled to the upstream tube portion and a second pair of thermal sensing elements are coupled to the downstream tube portion.

Abstract: A fluid flow rate measurement apparatus prevents accumulation of pollutional substances in a sub-passage to enable high-accuracy fluid flow rate measurement. A heater pattern is formed on the surface of a cylindrical rod. When electricity is conducted in the heater pattern and heat is generated, the heat is transmitted to the sub-passage through an insulating layer. The heat is gradually transmitted up to the leading end of the sub-passage, and burns out pollutional substances adhering to the sub-passage. In this way, accumulation in the sub-passage of pollutional substances can be prevented, thus attaining a fluid flow rate measurement apparatus that enables high-accuracy fluid flow rate measurement.

Abstract: An air flow measuring device includes a body with a main air passage and a sensor attached to the body for detecting a flow rate of air passing through the main air passage. A positioning part that positions the body and the sensor is configured to be exposed to the outside.

Abstract: A method, and apparatus therefor, for detecting the presence of a target amount of gas flowing within a conduit, including: providing a heating element in operational contact with the conduit; heating at least one of the conduit or the gas; measuring the temperature of at least one of the heating element, the conduit or the gas; comparing the measured temperature of at least one of the heating element, the conduit or the gas to data relating to a target temperature; controlling and measuring the amount of energy consumed by the heating element in order to maintain the target temperature; correlating the amount of energy consumed by the heating element in order to maintain the target temperature with an amount of gas flowing within the conduit; and determining whether the amount of gas flowing within the conduit is at least the target amount of gas flowing within the conduit.

Abstract: The invention relates to a sensor (102) and a control unit (702) for cooperation with the sensor. The sensor (102) serves for measuring a velocity of a fluid (308) flowing through a channel (306). The sensor (102) employs a thermal measuring principle, which measuring principle is robust regarding disturbances on the amount of power dissipated by the heating element (106). A sensor receiver (110) is arranged for receiving an electromagnetic radiation generated by a control transmitter (722) comprised in a control (702) unit for cooperation with the sensor (102). The electromagnetic radiation is employed for powering the heating element (106) which is arranged for heating the fluid. On the basis of a measurement signal generated by a transducer arrangement comprised in the sensor (102), a control actuator (724) controls the velocity of the fluid. For this purpose a sensor transmitter (116) is arranged for transmitting the measurement signal to a control receiver (734).

Abstract: Fluid flows through a conduit. To measure flow speed the fluid is heated at a heating location in the conduit with a time-dependent heating strength. A speed of sound in fluid flowing in the conduit is measured at a plurality of sensing locations downstream from said heating location. The flow speed of the fluid is determined from a delay with which the time dependence is detected in the sound speeds measured at said sensing locations. In an embodiment a frequency of the variation of heating strength that is used to determine the flow speed is selected automatically dependent on the flow speed and/or other circumstances.

Abstract: A mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or lightly doped P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.

Abstract: A flow sensor may include a heater for heating a partial region of the outer wall surface of a pipe forming a flow path or for heating a particular region in the pipe; and a temperature detector for measuring the temperatures of regions, the regions being on the upstream side and the downstream side of the pipe with respect to the heated region. The temperature detector may include an upstream-side non-contact temperature detector and a downstream-side non-contact temperature detector arranged near the outer wall surface of the pipe in a state of being not in contact with the outer wall surface, and the non-contact temperature detectors can measure the temperatures of the upstream-side heat energy radiating region and downstream-side heat energy radiating region in a state of being not in contact with the outer wall surface of the pipe.

Abstract: The invention relates to an apparatus for determining and/or monitoring mass flow of a fluid medium (3) through a pipeline (2), or through a measuring tube. The apparatus includes two temperature sensors (11, 12) and a control/evaluation unit (10). The two temperature sensors (11, 12) are arranged in a region of a housing (5) facing the medium (3) and in thermal contact with the medium (3) flowing through the pipeline (2), or through the measuring tube. A first of the temperature sensors (11) is heatably embodied. A second of the temperature sensors (12) provides information concerning the present temperature of the medium (3). The control/evaluation unit (10), on the basis of primary measured variables, such as temperature difference (?T=T2?T1) between the two temperature sensors (11, 12) and/or heating power (P) fed to the first temperature sensor (11), ascertains the mass flow of the medium (3) through the pipeline (2).

Abstract: Some embodiments of the present invention provide a system that determines a flow rate of air along an airflow path in a computer system. During operation the system monitors a first temperature profile from a first temperature sensor located in a first position in the airflow path, and monitors a second temperature profile from a second temperature sensor located in a second position in the airflow path, wherein the first position is upstream in the airflow path from the second position, and wherein the first position and the second position are separated by a predetermined distance along the airflow path. Next, the system computes a cross-power spectral density based on the first temperature profile and the second temperature profile. Then, the system determines a flow rate of air in the computer system based on the cross-power spectral density.

Abstract: A fluid flow rate sensor includes a detection circuit which generates a first signal corresponding to an output voltage of a bridge circuit, and a second signal corresponding to a fluid temperature. A control module can more accurately and quickly determine the fluid flow rate based on the first signal, the second signal and a look-up table. The look-up table includes a plurality of curves plotted according to data, indicating relationship among the fluid temperature, the output voltage and the fluid flow rate. The fluid flow rate sensor is inherently temperature compensated and has a shorter response time.

Abstract: A temperature compensating fluid flow sensing system is provided that comprises a resistance-based sensor element that is included in a constant voltage anemometer circuit configured to establish and maintain a command voltage across the first sensor element and to provide a constant voltage anemometer (CVA) output voltage corresponding to the resistance change in the first sensor element due to heat transfer between the first sensor element and the fluid. A controller is configured to establish the command voltage based on a desired overheat across the sensor and an actual overheat across the first sensor element. A power dissipation (PDR) module is configured to determine at least one fluid flow parameter and an actual overheat value based at least in part on the CVA output voltage and to transmit to the controller the actual overheat for use by the controller in updating the command voltage.