Abstract: A temperature measuring device for determining a medium temperature by a temperature of a measuring point on a surface enclosing the medium includes: at least one measuring sensor; at least one reference sensor; and a measured value processing device which is connected via a cable to the at least one measuring sensor and via a cable to the at least one reference sensor. The at least one measuring sensor and the at least one reference sensor are arranged along a main thermal connection path between the surface enclosing the medium and surroundings. The at least one measuring sensor is arranged close to the measuring point. A thermal resistance between a relevant measuring sensor and the at least one reference sensor is smaller than a thermal resistance between a relevant reference sensor and the surroundings.

Abstract: Systems and methods for limiting power of a gas turbine engine for an aircraft are described herein. A blade angle of a propeller blade of the engine and a commanded power for the engine are obtained. A thrust transition direction is determined. The commanded power is compared to a selected threshold based on the blade angle and the thrust transition direction. Power to the engine is limited when the commanded power exceeds the selected threshold.

Abstract: Preheat processes for a millisecond anneal system are provided. In one example implementation, a preheat process can include receiving a substrate on a wafer support plate in a processing chamber of a millisecond anneal system; obtaining one or more temperature measurements of the wafer support plate using a temperature sensor; and applying a preheat recipe to heat the wafer support plate based at least in part on the temperature of the wafer support plate. In one example implementation, a preheat process can include obtaining one or more temperature measurements from a temperature sensor having a field of view of a wafer support plate in a millisecond anneal system; and applying a pulsed preheat recipe to heat the wafer support plate in the millisecond anneal system based at least in part on the one or more temperature measurements.

Abstract: A device is disclosed herein, said device for determining whether a day is suitable for planting a seed on a plot of land, said device comprising a microprocessor programmed to: (a) select at least one electronic data source containing meteorological data and/or soil temperature for the plot of land by a method comprising: (a1) determining the location of the plot of land; and (a2) selecting a data source providing local weather forecasting services and/or soil data services for the location of the plot of land; (b) electronically receive from the at least one electronic data source: (b1) meteorological data for the plot of land comprising a high surface air temperature and a low surface air temperature for each of the plurality of consecutive days; and (b2) at least one soil temperature for each of the plurality of consecutive days; and (c) select an alpha day within the plurality of consecutive days and determine whether it is suitable for planting the seed based on the meteorological data, the soil tempera

Abstract: This underwater device is twin-motor underwater floating-type power generation device that is provided with: a device main body that is equipped with a pair of pods that have a turbine, and with a connecting beam that connects these pods together in parallel with each other; a sinker; and tether cables that tether the device main body to the seabed via this sinker. The respective turbines of the pods are each provided with variable pitch turbine blades. This device is also provided with a depth meter that detects deviation in posture in the roll direction that is generated in the pair of pods, and a posture controller that controls the pitch of the variable pitch turbine blades of the respective turbines so as to nullify any deviation in posture in the roll direction that has been generated in the pair of pods and has been detected by the depth meter.

Abstract: Systems, methods and apparatus are provided for soil testing. In some embodiments, a soil sample quality criterion is determined and associated with the soil sample. In some embodiments a soil characteristic measurement is additionally taken and associated with the soil sample. In some embodiments, the soil sample and its associated data are associated with a container in which the soil sample is placed.

Abstract: An electronic circuit device comprises an output part, which includes at least three phase parts and a first temperature sensor and a second temperature sensor, which output detection signals corresponding to temperatures of the output part. Each phase part includes two high-side and low-side switching elements. The first temperature sensor is located at a position between the first phase part and the second phase part. The second temperature sensor is located at a position between the second phase part and the third phase part. The electronic circuit device further comprises a control circuit part, which specifies a phase part of overheat among the phase parts based on the detection signals of the first temperature sensor and the second temperature sensor.

Abstract: There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

Abstract: A method of determining temperature ranges and setting performance parameters in a semiconductor device that may include at least one temperature sensing circuit is disclosed. The temperature sensing circuits may be used to control various operating parameters to improve the operation of the semiconductor device over a wide temperature range. The performance parameters may be set to improve speed parameters and/or decrease current consumption over a wide range of temperature ranges.

Abstract: A system for in-place visualization of sensed data is provided. The system includes a formable sheet comprising a display and sensors embedded within the sheet underneath the display. The display will display information relating to sensed data on a portion of the display corresponding to locations of the sensors located underneath the display. As a result, the display displays the information above or directly above the sensors that output data.

Abstract: A protection circuit includes: a temperature measuring unit which compares a voltage corresponding to a temperature at each of a plurality of sense points with a reference voltage, and generates a measurement result based on a result of comparison; a controller which generates a plurality of current control signals, which controls currents of a plurality of channels corresponding to the plurality of sense points, respectively, based on the measurement result from the temperature measuring unit; and a plurality of phase converter which outputs the currents of the plurality of channels based on the plurality of current control signals, wherein the controller generates the plurality of current control signals until the voltage corresponding to the temperature of each of the plurality of sense points is substantially equal to the reference voltage.

Abstract: An example adjustable linking member of a mounting assembly includes a first attachment portion and a second attachment portion. The first attachment portion connects a linking member to a first component. The second attachment portion connects the linking member to a second component. A variable portion of the adjustable linking member varies a distance between the first attachment portion and the second attachment portion in a first direction when heated. The variable portion varies the distance between the first attachment portion and the second attachment portion in a second direction when cooled. The first direction is opposite the second direction.

Abstract: An apparatus and method for sensing body temperature and wirelessly communicating measured data to at least one electronic device. The device includes a sensor device having a housing base, a housing cover releasably mountable on the housing base, and components for sensing body temperature and wirelessly communicating the measured temperature, including a temperature sensor, a power supply, a microprocessor, and a transmitter and receiver. The electronic device can include an application that communicates with the sensor device and provides a user interface.

Abstract: An apparatus and method for measuring, collecting, and processing the temperatures of a number of hot junctions in a thermocouple sensor array simultaneously comprises means for measuring the temperature of one or more reference junctions and means for collecting, processing, storing, and transmitting data collected from an array of thermocouple temperature sensors. The measured temperature(s) of the one or more reference junctions is used to correct the measured voltage in each of a plurality of thermocouple circuits to obtain accurate hot junction temperature measurements. The apparatus and method are particularly useful for collecting and processing temperature data from various locations within engines such as turbine, rocket, and internal combustion engines.

Abstract: A semiconductor apparatus includes a first structural body including a first temperature voltage generation unit configured to generate first and second temperature voltages which have different voltage level variations according to a temperature variation, in response to a temperature measurement command, and a first temperature information determination unit configured to generate first temperature information depending on a difference between levels of the first and second temperature voltages; and a second structural body including a second temperature voltage generation unit configured to generate a third temperature voltage and a fourth temperature voltage which have different voltage level variations according to a temperature variation, when a predetermined time elapses after the first and second temperature voltages are generated from the first structural body, and a second temperature information determination unit configured to generate second temperature information depending on a difference betwe

Abstract: Provided is a method of manufacturing a downhole cable, the method including, forming a helical shape in an outer circumferential surface of a metal tube, the metal tube having a fiber element housed therein, and stranding a copper element in a helical space formed by the metallic tube. Also provided is a downhole cable including, a metallic tube having a helical space in an outer circumferential surface thereof, wherein the metallic tube has a fiber element housed therein, and a copper element disposed in a helical space formed by the steel tube. Double-tube and multi-tube configurations of the downhole cable are also provided.

Abstract: Some embodiments of the present disclosure relate to a stacked integrated chip structure having a thermal sensor that detects a temperature of one or a plurality of integrated chips. In some embodiments, the stacked integrated chip structure has a main integrated chip and a secondary integrated chip located on an interposer wafer. The main integrated chip has a reference voltage source that generates a bias current. The secondary integrated chip has a second thermal diode that receives the bias current and based thereupon generates a second thermal sensed voltage and a second reference voltage that is proportional to a temperature of the secondary integrated chip. A digital thermal sensor within the main integrated chip determines a temperature of the secondary integrated chip based upon as comparison of the second thermal sensed voltage and the reference voltage.

Abstract: A fault diagnosis device conducts a fault diagnosis in a temperature sensor. At starting an internal combustion engine, a thermal equilibrium condition may be established and temperature deviations of temperatures detected by at least two reference temperature sensors from each other may be equal to or less than a predetermined value, with the temperatures detected by the reference temperature sensors being greatly deviated from one detected by a temperature sensor being diagnosed. In this case, if the temperatures detected by the reference temperature sensors do not drop by a predetermined temperature or more from starting the engine until a predetermined time elapses, the fault diagnosis device determines that the temperature sensor being diagnosed is faulty.

Abstract: A mechanism for indicating ambient temperature of an enclosure from temperatures determined within the enclosure. The temperatures may be obtained from two or more sensors at each of two or more locations within the enclosure. The enclosure may include an apparatus inside such as electronics of which power consumption may be determined. Data including temperatures of two locations within the enclosure at various electronics power consumption levels may be entered into a 2-D plot. An approximation of the 2-D plot may be effected with an appropriate equation to be solved for ambient temperature. The data of the 2-D plot plus temperatures of a third location and air flow levels in the enclosure may be entered into a 3-D plot. An approximation of the 3-D plot may be effected with an appropriate equation to be solved for ambient temperature.

Abstract: A mechanism for indicating ambient temperature of an enclosure from temperatures determined within the enclosure. The temperatures may be obtained from two or more sensors at each of two or more locations within the enclosure. The enclosure may include an apparatus inside such as electronics of which power consumption may be determined. Data including temperatures of two locations within the enclosure at various electronics power consumption levels may be entered into a 2-D plot. An approximation of the 2-D plot may be effected with an appropriate equation to be solved for ambient temperature. The data of the 2-D plot plus temperatures of a third location and air flow levels in the enclosure may be entered into a 3-D plot. An approximation of the 3-D plot may be effected with an appropriate equation to be solved for ambient temperature.

Abstract: Devices and corresponding methods can be provided to measure temperature and/or emissivity of a target. Emissivity of the target need not be known or assumed, and any temperature difference between a sensor and the target need not be zeroed or minimized. No particular bandpass filter is required. Devices can include one or two sensors viewing the same target as the target views different respective viewed temperatures. The respective viewed temperatures can be sensor temperatures, and a single sensor can be set to each of the respective viewed temperatures at different times. An analyzer can determine the temperature and/or emissivity of the target based on the respective viewed temperatures and on plural net heat fluxes detected by the sensors and corresponding to the respective viewed temperatures.

Abstract: A combination fire detection and fire suppression system may include a fire detection system configured to detect an undesirably high temperature associated with an area. The fire detection system may include a temperature sensor including a temperature sensor array and a fire alerting system associated with the temperature sensor. The fire alerting system may be configured to receive information from the temperature sensor and generate a warning signal based on an undesirably high temperature associated with the area. The fire detection system may include a fire control panel configured to receive the warning signal. The system may also include a fire suppression system including a fire suppressant delivery system configured to provide at least one fire suppressant agent to the area associated with the undesirably high temperature.

Abstract: The present invention is directed to, inter alia, systems and methods for calculating a temperature associated with an analyte measurement component of a biosensing instrument (such as a blood glucose monitor), with a test strip that is inserted in a biosensing instrument, or both. The present systems and methods may employ at least two temperature sensors, and the acquired temperature information may be used to modulate data regarding an analyte in a biological sample, thereby providing a more accurate measurement of the analyte.

Abstract: A magnetic sensor inspection apparatus has a rectangular frame including a stage, a probe card, and a plurality of magnetic field generating coils. A wafer-like array of magnetic sensors is mounted on the stage, which is movable in horizontal and vertical directions. The probe card includes a plurality of probes which are brought into contact with a plurality of magnetic sensors encompassed in a measurement area. The magnetic field generating coils are driven to generate a magnetic field toward the stage. A plurality of magnetic field environment measuring sensors is arranged in the peripheral portion of the probe card surrounding the probes. A magnetic field controller controls magnetic fields generated by the magnetic field generating coils based on the measurement result of the magnetic field environment measuring sensors. Thus, it is possible to concurrently inspect a wafer-like array of magnetic sensors with the probe card.

Abstract: A method and system are implemented for monitoring the thermal dissipation from a computer processing unit. The system comprises a temperature sensor, and a temperature controller. The temperature controller is configured to set a temperature observation window in a first temperature range, gradually narrow the observation window from the first temperature range after a monitored temperature of the processing unit has entered the observation window, and issue an alert signal when the monitored temperature exits the observation window.

Abstract: A thermometer includes first and second surface temperature measurement units, first and second reference temperature measurement units, a storage unit, a temperature correction unit, and a temperature calculation unit. The first reference temperature measurement unit measures a temperature at an opposite side of the first surface temperature measurement unit as a first reference temperature through a first heat insulating portion having a first thermal resistance value. The second reference temperature measurement unit measures a temperature at an opposite side of the second surface temperature measurement unit as a second reference temperature through a second heat insulating portion having a second thermal resistance value. The temperature correction unit corrects the first surface temperature and the first reference temperature based on the second surface temperature and the second reference temperature.

Abstract: A temperature measurement device includes a first surface temperature measurement part performing a measurement to be used as a first surface temperature; a first reference temperature measurement part performing a measurement to be used as a first reference temperature; a first external air temperature measurement part performing a measurement to be used as a first external air temperature; a second surface temperature measurement part performing a measurement to be used as a second surface temperature; a second reference temperature measurement part performing a measurement to be used as a second reference temperature; a second external air temperature measurement part performing a measurement to be used as a second external air temperature; a deep-part temperature computation part computing the deep-part temperature of a subject to be measured; and an external air temperature computation part computing the external air temperature of the external air.

Abstract: A method for calibrating distributed temperature sensing (DTS) systems is disclosed. The method includes: receiving temperature data associated with one or more locations along a length of an optical fiber; calculating a set of unique calibration coefficients specific to each of the one or more locations along the fiber length; and applying the set of calibration coefficients specific to each of the one or more locations along the fiber length to the temperature data for calibrated correction thereof. Also disclosed is a system for calibrating DTS data and a wellbore for providing calibrated DTS data.

Abstract: A thermometer includes a first surface temperature measurement unit; a first reference temperature measurement unit; a second surface temperature measurement unit; a second reference temperature measurement unit; a temperature correction unit that calculates a mounting positional difference between the first and second surface temperature measurement units from a measurement subject and a mounting positional difference between the first and second reference temperature measurement units from the measurement subject in terms of temperature differences that compensate for temperature dependence, thus correcting the first surface temperature and first reference temperature, or the second surface temperature and second reference temperature; and a core temperature calculation unit that calculates a core temperature of the measurement subject using the first surface temperature and first reference temperature or the second surface temperature and second reference temperature corrected by the temperature correction

Abstract: A system for in-place visualization of sensed data is provided. The system includes a formable sheet comprising a display and sensors embedded within the sheet underneath the display. The display will display information relating to sensed data on a portion of the display corresponding to locations of the sensors located underneath the display. As a result, the display displays the information above or directly above the sensors that output data.

Abstract: An exemplary embodiment of a temperature probe comprises an elongated shaft having a first portion and a second portion, the first portion being configured for insertion into a unit of food and the second portion being configured to extend outside of the unit of food. The probe further comprises at least two temperature sensors positioned at different longitudinal locations along the first portion of the shaft that are configured to measure temperatures of the unit of food at different locations within the unit of food while the unit of food is being processed thermally. The probe further comprises at least one ambient temperature sensor coupled to the shaft and configured to measure ambient temperature adjacent to the unit of food.

Abstract: A device for detecting temperature variations of the substrate of an integrated circuit chip, including, in the substrate, implanted resistors connected as a Wheatstone bridge, wherein each of two first opposite resistors of the bridge is covered with an array of metal lines parallel to a first direction, the first direction being such that a variation in the substrate stress along this direction causes a variation of the unbalance value of the bridge.

Abstract: A method of using a temperature sensor to determine the temperature of an object is described. The method comprises bringing the temperature sensor into thermal contact with the object to be measured. The temperature sensor is then used to acquire a plurality of temperature readings, the plurality of temperature readings being acquired prior to the temperature sensor reaching thermal equilibrium with the object. At least some of the plurality of temperature readings are then used to determine a pseudo-stable temperature at which the rate of change of temperature readings with time is less than a predetermined rate. The actual temperature of the object may then be predicted from the pseudo-stable temperature.

Abstract: An ice detection system, in particular to a system for detecting icing conditions and a system for detecting the presence of ice formed on a structure, and the methods for doing the same. Two heaters of the ice protection system (experiencing substantially the same environmental conditions) are driven to different temperatures (the first greater than or equal to 0° C., and the second less than 0° C.). The difference in the powers required to drive the two heaters indicates the prevailing environmental conditions. A heater of the ice protection system is driven and the rate of change of surface temperature is measured over several periods. A substantial deviation from a rate of change of surface temperature, which indicates the presence of ice on the surface of the structure, is detected.

Abstract: A method of sensing defects in the application of hot melt adhesive to a structure. An infrared sensor is used to capture an infrared image of at least the location of the structure where the adhesive is supposed to have been applied. Different areas of the image are separately interrogated by reviewing each area to detect the presence or absence of adhesive. The interrogation is used to determine whether or not the application of the adhesive is of acceptable quality.

Abstract: A system and method are disclosed wherein differential heat transfer resistances are used to effectively and efficiently detect the early onset of deposit accumulation in industrial fluid processes and fluid transport vehicles. According to one embodiment, a probe is provided in conjunction with a heat source, a water source and a probe. The probe is comprised of a heat transfer surface, a first part of which is covered only by a thin metal layer. The second or remaining portion of the heat transfer surface is covered by a heat flux sensor and a thin metal layer. The metal layers of both the first and second areas of the probe are connected, and water flows across the full heat transfer surface. Deposition forms on a portion of the heat transfer surface as a result of slow water flow and elevated water temperature. The temperatures of the heat source, water source, and heat flux are measured. The deposition rate as a rate of change of heat transfer resistance is measured.

Abstract: A device for analyzing a beam profile of a laser beam includes a carrier plate, a plurality of first temperature-sensitive measuring elements, in particular diodes, which are arranged in a preferably matrix-like arrangement on a first side of the carrier plate at a plurality of measuring locations, and a plurality of second temperature-sensitive measuring elements, in particular diodes, which are arranged in another preferably matrix-like arrangement on a second side of the carrier plate. One of the first measuring elements is arranged in each case opposite one of the second measuring elements and is thermally coupled to the first measuring element using strip conductors which extend through the carrier plate. Such a device can be included in a laser processing machine and used in an associated method for analyzing a beam profile of a laser beam.

Abstract: An exemplary embodiment of a temperature probe comprises an elongated shaft having a first portion and a second portion, the first portion being configured for insertion into a unit of food and the second portion being configured to extend outside of the unit of food. The probe further comprises at least two temperature sensors positioned at different longitudinal locations along the first portion of the shaft that are configured to measure temperatures of the unit of food at different locations within the unit of food while the unit of food is being processed thermally. The probe further comprises at least one ambient temperature sensor coupled to the shaft and configured to measure ambient temperature adjacent to the unit of food.

Abstract: The invention is related to methods for determining thermophysical properties of solid bodies, particularly, to methods for determining thermal conductivity and volumetric heat capacity. In accordance with the method, a reference sample and sequentially located samples of solid bodies are heated by a thermal energy source moving at a constant speed relative to the reference sample and the samples being studied. Excessive temperatures of the surfaces of the reference sample and the studied samples at points on a line of heating are measured and the thermophysical properties of the reference sample and the samples being studied are determined. Arbitrary shape samples are used and thermal conductivity and volumetric heat capacity of the samples are determined by solving an inverse coefficient problem of thermal conductivity.

Abstract: An assembly for sensing temperature in a gas turbine engine includes a first array of RTDs connected in parallel, a second array of RTDs connected in parallel, and a circuit electrically connected to the first and second arrays. The circuit determines an approximate temperature of a medium as a function of resistance of the first and second arrays.

Abstract: A method for measuring the temperature at various locations in a furnace adapted to heat-treat a metal part commences by placing one or more devices at various location within the furnace. Each device is an inorganic/metallic skeletal structure residual from firing a mixture of binder and one or more of inorganic or metallic particles at a temperature that chars the binder to form the inorganic/metallic skeletal structure of a determined shape. A physical parameter of the skeletal structure determined shape is monitored after firing of the furnace. Then, the monitored physical parameter is compared to a plot of temperature versus the physical parameter to determine the temperature of the furnace at the various locations.

Abstract: The present invention is directed to, inter alia, systems and methods for calculating a temperature associated with an analyte measurement component of a biosensing instrument (such as a blood glucose monitor), with a test strip that is inserted in a biosensing instrument, or both. The present systems and methods may employ at least two temperature sensors, and the acquired temperature information may be used to modulate data regarding an analyte in a biological sample, thereby providing a more accurate measurement of the analyte.

Abstract: A physical quantity detecting apparatus includes a plurality of physical quantity conversion circuits, an output selection circuit and a signal conversion circuit. Each of the plurality of physical quantity conversion circuits converts a physical quantity to be detected into a voltage corresponding to the physical quantity and outputs the voltage. The output selection circuit is electrically connected to the plurality of physical quantity conversion circuits to select a maximum voltage from among the voltages outputted from the plurality of physical quantity conversion circuits. The signal conversion circuit is electrically connected to the output selection circuit to convert the voltage outputted from the output selection circuit into a pulse signal having a pulse width or frequency corresponding to the voltage and output the pulse signal.

Abstract: A temperature sensor is formed from three initially unfired (or green) ceramic substrates. The first substrate has a temperature sensitive means printed on a first surface. Additionally first and second conducting elements are also printed thereon. The third substrate has a temperature sensitive means in the form of a resistor printed on a first surface. Additionally first and second conducting elements and are also printed thereon. The second substrate is provided with a conducting via in the form of a hole extending through the substrate, the hole being filled with conductive material. The via is adapted to be aligned with the ends of conducting elements. To construct the sensor the first surfaces of substrates are aligned with substrate such that via is aligned with conducting elements. The substrates are then pressed together. Subsequently the substrates are fired to provide the completed sensor.

Abstract: The present invention is directed to, inter alia, systems and methods for calculating a temperature associated with an analyte measurement component of a biosensing instrument (such as a blood glucose monitor), with a test strip that is inserted in a biosensing instrument, or both. The present systems and methods may employ at least two temperature sensors, and the acquired temperature information may be used to modulate data regarding an analyte in a biological sample, thereby providing a more accurate measurement of the analyte.

Abstract: A heat flux probe uses a thermoelectric module to heat a relatively large sensing surface while cooling a substantially smaller one that is connected to the thermoelectric module by an elongated thermal conductor. A temperature difference between either the two sensing surfaces or the heated sensing surface and the cooled end plate of the thermoelectric module is controlled to have a selected value. Then the temperature change along the elongated thermal conductor is used as a measure of heat flux. This approach reduces inaccuracies arising from the thermal characteristics of the thermoelectric module and allows for in situ compensation for drift errors.

Abstract: A mechanism for indicating ambient temperature of an enclosure from temperatures determined within the enclosure. The temperatures may be obtained from two or more sensors at each of two or more locations within the enclosure. The enclosure may include an apparatus inside such as electronics of which power consumption may be determined. Data including temperatures of two locations within the enclosure at various electronics power consumption levels may be entered into a 2-D plot. An approximation of the 2-D plot may be effected with an appropriate equation to be solved for ambient temperature. The data of the dimensional 2-D plot plus temperatures of a third location and air flow levels in the enclosure may be entered into a 3-D plot. An approximation of the 3-D plot may be effected with an appropriate equation to be solved for ambient temperature.

Abstract: A method judging a temperature of a chip including using a limited set of temperature sensors and using a knowledge of a power dissipation, estimating a temperature on a surface of a chip and predicting a future temperature of the chip knowing the instruction stream characteristics to be processed by the chip.

Abstract: A screening device and a method are described herein which can automatically handle and measure (interrogate) a plurality of sensor carriers (i.e., multiwell plates, microplates) with multi-dimensionally arranged, temperature-compensated or temperature-compensatable optical sensors, while maintaining a substantially constant temperature gradient for a relatively long period of time around the optical sensors where temperature compensation has been performed on the sensor carriers.

Abstract: A fast response temperature probe which may be used for a method for measuring an instantaneous temperature of a periodically changing fluid flow within a gas turbine is proposed. The temperature probe includes a substrate and a resistive element arranged at a surface of the substrate. Therein, at least at a surface of the substrate contacting the resistive element, the substrate comprises an insulating material having a thermal product of less than 1.5 kJ/(m2K sqrt(s)). The substrate or at least its surface is made from polyamide-imide such as for example fibre-reinforced Torlon© 5030. The temperature probe may allow measurements of instantaneous local temperatures of very fast fluctuations of more than 50 kHz at high spatial resolutions of, e.g., less than 0.5 mm2. The instantaneous temperature of a periodically changing fluid flow may be determined by correlating first and second sets of temperature measurements taking into account the periodicity of the periodically changing fluid flow.