Temperature measuring device, and temperature calibration method for same

Abstract

Provided are: a temperature measuring device capable of measuring a temperature with high accuracy without being affected by variations in the resistance value of a thermistor element, variations in a reference resistance value, variations in the temperature coefficient of each resistance value, and fluctuations in a power supply voltage; and a temperature calibration method for the temperature measuring device.　The temperature measuring device comprises a compound sensor in which a thermistor element Rt and a resistor element Rr are disposed in the same temperature region and are connected in series. The temperature measuring device is provided with an information processing unit 2 which: energizes the compound sensor and either measures the resistance values of the thermistor element Rt and the resistor element Rr, or measures the terminal-to-terminal voltage values of the thermistor element Rt and the resistor element Rr; accepts input of measurement values obtained by the measurement; calculates, from the measurement values, either a ratio between the resistance values of the thermistor element Rt and the resistance element Rr, or a ratio between the terminal-to-terminal voltage values of the thermistor element and the resistor element; and outputs temperature information on the basis of the ratio between the resistance values or the ratio between the terminal-to-terminal voltage values.

Description

Temperature measuring device and its temperature calibration method

[0001] The present invention relates to a temperature measurement device and a temperature calibration method for a temperature measurement device.

[0002] Conventionally, for example, in a temperature sensor using a thermistor as a temperature measuring device, a reference resistor element is connected to the thermistor element, and the voltage value across the reference resistor element at a constant temperature or the voltage value across the thermistor element is extracted and converted into temperature information by AD conversion, etc. In this case, the thermistor element is placed in the measuring unit (sensor unit), and the reference resistor element is placed in the measuring device main body connected by lead wires.

[0003] Therefore, the temperature environments of the thermistor element and the reference resistor element are different, and this temperature difference causes a difference in the temperature characteristics of the thermistor element and the reference resistor element, making it difficult to measure temperature with high accuracy.

[0004] Therefore, temperature sensors have been proposed that improve the accuracy of temperature measurement by placing the thermistor element and the reference resistance element in the same temperature environment (see Patent Documents 1 to 4).

[0005] JP 6-310305 JP 7-111206 JP 2008-153525 Patent No. 4845512

[0006] On the other hand, when measuring temperature by supplying power from a power supply to a thermistor element and a reference resistance element, fluctuations in the power supply voltage occur, causing a decrease in the accuracy of the temperature measurement.Furthermore, there is a problem that the temperature accuracy deteriorates due to variations in the resistance value of the thermistor element, variations in the reference resistance value, and variations in the temperature coefficients of each.

[0007] An embodiment of the present invention aims to provide a temperature measuring device and a temperature calibration method thereof that are capable of highly accurate temperature measurement that is not affected by fluctuations due to power supply voltage, variations in each resistance value, and variations in the temperature coefficient of each resistance value.

[0008] A temperature measuring device according to an embodiment of the present invention is characterized in that it includes a composite sensor arranged in the same temperature region and having a thermistor element and a resistor element connected in series, and is configured to pass current through the composite sensor to measure the resistance values ​​of the thermistor element and resistor element or the voltage value between the terminals of the thermistor element and resistor element, and is further configured to input the measured values ​​and calculate the ratio of the resistance values ​​of the thermistor element and resistor element or the ratio of the voltage values ​​between the terminals of the thermistor element and resistor element from the measured values, and output temperature information based on the ratio of the resistance values ​​or the ratio of the voltage values ​​between the terminals.

[0009] Furthermore, a temperature measuring device according to an embodiment of the present invention is characterized in that it includes a composite sensor arranged in the same temperature region and having a thermistor element and a resistive element connected in series, and is further characterized in that it passes current through the composite sensor to measure a voltage value between the terminals of the thermistor element or resistive element, has an information processing unit that receives the measured value, calculates a ratio between the measured voltage value between the terminals of the thermistor element or resistive element and a power supply voltage value, and digitally outputs temperature information based on the voltage ratio.

[0010] A temperature calibration method according to an embodiment of the present invention is a temperature measurement device including a composite sensor arranged in the same temperature region and having a thermistor element and a resistor element connected in series, wherein current is passed through the composite sensor to measure the resistance values ​​of the thermistor element and the resistor element or the voltage value between the terminals of the thermistor element and the resistor element, the measured value being input, the information processing unit calculating a ratio of the resistance values ​​of the thermistor element and the resistor element or a ratio of the voltage values ​​between the terminals of the thermistor element and the resistor element from the measured value, and outputting temperature information based on the ratio of the resistance values ​​or the ratio of the voltage values ​​between the terminals, wherein temperature calibration is performed using the composite sensor in which the thermistor element and the resistor element are connected in series as a reference composite sensor and a composite sensor to be calibrated.

[0011] In the temperature calibration method of this embodiment, the composite sensor and the information processing unit, for example, the microcomputer, are calibrated in a one-to-one combination, so that a highly accurate sensor system can be constructed that also takes into account the variations and characteristics of the voltage measurement of the microcomputer.

[0012] According to an embodiment of the present invention, it is possible to provide a temperature measuring device and a temperature calibration method thereof that are capable of highly accurate temperature measurement that is not affected by fluctuations due to power supply voltage, variations in the resistance value of the thermistor, variations in the reference resistance value, and variations in the temperature coefficient of each resistance value.

[0013] FIG. 1 is a conceptual diagram schematically showing a temperature measuring device according to a first embodiment of the present invention. FIG. 2 is a configuration diagram showing the temperature measuring device. FIG. 3 is a flow diagram showing the operation of the temperature measuring device. FIG. 4 is a data table showing the correlation between temperature and the ratio of the resistance values ​​of a thermistor element and a resistor element. FIG. 5 is a conceptual diagram schematically showing another example of a wiring state. FIG. 6 is a structural diagram schematically showing a composite sensor in the temperature measuring device (Example 1). FIG. 7 is a structural diagram schematically showing a composite sensor in the temperature measuring device (Example 2). FIG. 8 is a structural diagram schematically showing a composite sensor in the temperature measuring device (Example 3). FIG. 9 is a conceptual diagram schematically showing a temperature measuring device according to a second embodiment of the present invention. FIG. 10 is a conceptual diagram schematically showing a temperature measuring device according to a third embodiment of the present invention.

[0014] [First Embodiment] A temperature measuring device according to a first embodiment of the present invention will be described below with reference to Figures 1 to 5. Figure 1 is a conceptual diagram showing a typical temperature measuring device, and Figure 2 is a configuration diagram showing the temperature measuring device. Figure 3 is a flow diagram showing the operation of the temperature measuring device, Figure 4 is a data table showing the correlation between temperature and the ratio of the resistance values ​​of the thermistor element and the resistor element, and Figure 5 is a conceptual diagram showing a typical example of another wiring state. Note that the same or corresponding parts are designated by the same reference numerals, and duplicate explanations will be omitted.

[0015] An embodiment of the present invention is a temperature measuring device that includes a composite sensor arranged in the same temperature region and having a thermistor element and a resistor element connected in series, and that measures the resistance values ​​of the thermistor element and the resistor element or the voltage values ​​between the terminals of the thermistor element and the resistor element by passing current through the composite sensor, calculates the ratio of the resistance values ​​of the thermistor element and the resistor element or the ratio of the voltage values ​​between the terminals of the thermistor element and the resistor element from the measured values, and outputs temperature information based on these ratios.

[0016] 1, the temperature measuring device 1 includes a thermistor element Rt, a resistor element Rr, a control processing unit 2, and a DC power supply 3. The thermistor element Rt and the resistor element Rr are connected in series to form a composite sensor.

[0017] The thermistor element Rt is an NTC (Negative Temperature Coefficient) thermistor of a thermistor composition, and is made of an oxide semiconductor having a negative temperature coefficient, such as two or more elements selected from transition metal elements such as manganese (Mn), nickel (Ni), cobalt (Co), and iron (Fe).

[0018] The resistor element Rr serves as a reference resistor and is connected in series with the thermistor element Rt, thus forming a series circuit in which the thermistor element Rt and the resistor element Rr are connected in series.

[0019] The thermistor element Rt and the resistor element Rr are arranged in the measuring unit 4, which is a sensor unit, and are configured so that the thermistor element Rt and the resistor element Rr are in the same temperature environment. For example, the measuring unit 4 in the same temperature environment is configured by arranging the thermistor element Rt and the resistor element Rr in a minute space or by mounting the thermistor element Rt and the resistor element Rr on the same substrate.

[0020] The control processing unit 2 is specifically a microcomputer (hereinafter referred to as "mc"), which performs overall control by executing a predetermined program and processes information.

[0021] In the above configuration, both ends of the series circuit of the thermistor element Rt and the resistor element Rr and the intermediate connection point of the thermistor element Rt and the resistor element Rr are connected to a microcomputer. The microcomputer receives the terminal voltages Vt and Vr as measured values ​​of the thermistor element Rt and the resistor element Rr, and the applied voltage V, as outputs from the series circuit. The microcomputer then calculates the ratio of the terminal voltages of the thermistor element Rt and the resistor element Rr from the input terminal voltages Vt and Vr and the applied voltage V, and outputs temperature information based on this ratio. A DC power supply 3 supplies power to the series circuit (composite sensor) of the thermistor element Rt and the resistor element Rr and to the microcomputer.

[0022] Next, the configuration and operation of the temperature measuring device of this embodiment will be described with reference to Figure 2. The temperature measuring device 1 includes a composite sensor of a thermistor element Rt and a resistor element Rr, a control processing unit 2, and a power supply 3. The microcomputer that constitutes the control processing unit 2 is generally composed of a CPU 21 having a calculation unit and a control unit, a ROM 22 and RAM 23 that serve as storage means, an input / output control unit 24, and an AD converter 25. The power supply 3 supplies power to the composite sensor and the microcomputer.

[0023] 3, in this configuration, power is supplied from the DC power supply 3 and energized (step S1), and the inter-terminal voltage value Vout1-Vout2 of the resistor element Rr, i.e., Vr, is output. Also, the inter-terminal voltage value Vout2-Vout3 of the thermistor element Rt, i.e., Vt, is output (step S2). These outputs are AD converted by the AD converter 25 of the microcomputer, and digital signals representing the measurement values ​​of the thermistor element Rt and the resistor element Rr are input to the input / output control means 24 (step S3). The microcomputer calculates the ratio of the inter-terminal voltage values ​​of the thermistor element Rt and the resistor element Pr from the input inter-terminal voltage values ​​Vt and Vr (step S4).

[0024] The microcomputer's storage means stores data and a conversion program showing the correlation between temperature and terminal voltage ratio, and the microcomputer refers to this data table (step S5). Then, based on this terminal voltage ratio, the microcomputer records temperature data in the storage means. The recorded data is used to calculate temperature information, which is then output (O / P) as digital data from the input / output control means 24 via a serial digital interface (SDI) (step S6). This digital data is then serially transmitted, for example, via wire or wireless, to an external processing system, such as the measuring device itself.

[0025] In this way, temperature information is output based on the ratio of the voltage values ​​between the terminals of the thermistor element Rt and resistor element Rr, so even if there is a voltage fluctuation in the DC power supply 3, it is possible to perform highly accurate temperature measurement that is not affected by fluctuations in the applied voltage V of the DC power supply 3. Furthermore, by using the applied voltage V as a common reference power supply for the AD converter 25 of the microcomputer, it is possible to reduce conversion errors in the AD converter 25 even if the applied voltage V fluctuates.

[0026] The resistance values ​​of the thermistor element Rt and the resistor element Rr can be measured, the ratio of the resistance values ​​of the thermistor element Rt and the resistor element Rr can be calculated from the measured values, and temperature information can be output based on this ratio. The ratio of the resistance values ​​of the thermistor element Rt and the resistor element Rr can be calculated from the measured resistance values ​​of the thermistor element Rt and the resistor element Rr, and temperature information can be output from the input / output control means 24 based on this ratio. The resistance ratio (resistance ratio) is calculated by dividing the resistance value of the thermistor by (resistance value of the thermistor + resistance value of the fixed resistor). The resistance value of the reference resistor element Rr changes with temperature, but the temperature of the measuring unit 4 can be identified using the resistance value of the thermistor element Rt, and the resistance value of the resistor element Rr can be corrected at that temperature, allowing for more accurate measurement of the resistance value of the thermistor element Rt.

[0027] In this case, a data table showing the correlation between temperature and resistance value ratio (resistance ratio) as shown in FIG. 4 is stored in the storage means of the microcomputer, and the microcomputer refers to this data table.

[0028] Therefore, in the same way as when temperature information is output based on the ratio of terminal voltage values, temperature information is output based on the ratio of the resistance values ​​of the thermistor element Rt and the resistor element Rr, which enables highly accurate temperature measurement that is not affected by fluctuations in the applied voltage V of the DC power supply (voltage source) 3.

[0029] Alternatively, the voltage across the thermistor element Rt or the resistor element Rr may be measured, the measured value input to a microcomputer, the ratio of the measured voltage across the thermistor element Rt or the resistor element Rr to the voltage of the power supply 3 calculated, a data table showing the correlation between temperature and voltage ratio, and temperature information output based on this voltage ratio. In this case, either the voltage across the resistor element Rr (Vr) or the voltage across the thermistor element Rt (Vt) shown in FIG. 1 may be omitted. Temperature information can be obtained by calculating the ratio between the power supply voltage and the voltage across the terminals (Vt or Vr).

[0030] As in the case described above, even if there are some fluctuations in the power supply voltage value, the voltage ratio does not change, so that highly accurate temperature measurement is possible.

[0031] Another example of the wiring state of the temperature measuring device will be described with reference to Figure 5. Figure 5 shows the wiring state when measuring temperature using the four-terminal method. For example, if the microcomputer and the composite sensor are far apart, the resistance of the connecting wiring will be added to the thermistor element Rt and the resistor element Rr, causing an error in the temperature measurement.

[0032] When using the four-terminal method, the resistance value is measured by measuring only the voltage value (voltage drop value) between the terminals of the composite sensor by separating the wiring of the series circuit of the thermistor element Rt and resistor element Rr, through which current I flows from the DC power supply (current source) 3, from the wiring that measures the voltage on the microcontroller side. By connecting in this way based on the four-terminal method, errors due to wiring resistance are eliminated, allowing for more accurate resistance value measurement.

[0033] Next, an embodiment of the composite sensor will be described with reference to Figures 6 to 8. Figures 6 to 8 are structural diagrams that schematically show the composite sensor. In each figure, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be omitted. In addition, the scale of each part has been appropriately changed for the purpose of explanation so that each part can be recognized.

[0034] Example 1 As shown in Figure 6, the composite sensor has a thin-film thermistor element Rt and a thin-film resistor element Rr formed on an alumina substrate connected in series. These thin-film thermistor element Rt and thin-film resistor element Rr are formed on a substrate 5. Specifically, the thermistor element Rt and resistor element Rr are formed by depositing thin films by sputtering on an insulating substrate 5, which is a ceramic substrate or glass substrate. Electrode layers 6 are connected to the thermistor element Rt and resistor element Rr. Lead wires, which are wiring 7, are connected to these electrode layers 6 by solder or the like.

[0035] The composite sensor has a horizontal dimension of 6.0 to 8.0 mm, a vertical dimension of 2.0 to 3.0 mm, and a total thickness of 60 μm. In addition, the thickness of the substrate 5 is 1 μm to 100 μm. Therefore, the composite sensor is placed in an extremely small space, and the thermistor element Rt and the resistor element Rr are placed in the same temperature range and can be kept at the same temperature.

[0036] Example 2 As shown in Figure 7, the composite sensor is configured by connecting a chip-type thermistor element Rt and a chip-type resistor element Rr made of bulk material in series. The diagram shows a wiring state based on the four-terminal method, with lead wires (7) connected to the electrode layers 6 of the thermistor element Rt and resistor element Rr by solder or the like. 7a is a current source wire connected to the current end of the thermistor element Rt, 7b is a voltage measurement wire connected to the voltage end of the thermistor element Rt, and 7c is a voltage measurement wire connected to the voltage end of the intermediate connection point. 7d is a voltage measurement wire connected to the current end of the resistor element Rr, and 7e is a current source wire connected to the voltage end of the thermistor element Rt.

[0037] By connecting the wires based on the principle of the four-terminal method, errors in wiring resistance are eliminated, enabling more accurate resistance measurement.

[0038] Since it is based on the principle of the four-terminal method, the wiring of the series circuit through which current flows and the wiring for measuring voltage are separated. The composite sensor can be sealed in resin or glass. Incidentally, the size of the chip-type thermistor element Rt is 1 mm x 0.5 mm x 0.6 mm.

[0039] Such a composite sensor is small and can be placed in a small space, so the thermistor element Rt and the resistance element Rr can be placed in the same temperature range and maintained at the same temperature.

[0040] (Example 3) As shown in Figure 8, the composite sensor shows a wiring state based on the principle of the four-terminal method, and has a thin-film thermistor element Rt and a thin-film resistor element Rr formed on a substrate 5. The thermistor element Rt and resistor element Rr are formed by sputtering thin films on an insulating substrate 5, such as a ceramic or glass substrate, or on a high-temperature resistant plastic film. Electrode layers 6 are connected to the thermistor element Rt and resistor element Rr. A metal oxide film or a metal grace film is used for the thin-film resistor element Rr. It is also possible to form a microfabricated platinum vapor deposition film circuit by sputtering or the like and use it as a reference resistor film.

[0041] Each lead wire, or wiring 7, is connected to the electrode layer 6 of the thermistor element Rt or resistor element Rr by solder or the like. 7a is a current source wiring connected to the current end of the thermistor element Rt, 7b is a voltage measurement wiring connected to the voltage end of the thermistor element Rt, 7c is a voltage measurement wiring connected to the voltage end of the intermediate connection point, 7d is a voltage measurement wiring connected to the current end of the resistor element Rr, and 7e is a current source wiring connected to the voltage end of the thermistor element Rt.

[0042] By connecting the wires based on the principle of the four-terminal method, errors in wiring resistance are eliminated, enabling more accurate resistance measurement.

[0043] Since the thin film thermistor element Rt and the thin film resistor element Rr are formed on the same substrate 5, the temperatures of the two become extremely uniform, and the thin film thermistor element Rt and the thin film resistor element Rr are disposed in the same temperature region.

[0044] [Second embodiment] Next, a temperature measuring device according to a second embodiment will be described with reference to Fig. 9. This embodiment has a plurality of composite sensors, specifically three composite sensors, which are connected to a microcomputer that is a control processing unit 2. The microcomputer detects a plurality of voltages Vt １ , Vt ２ and Vt ３ Thermistor element Rt has a function of measuring the voltage Vt between its terminals. １ , Vt ２ and Vt ３ The measured value is input to the microcomputer, which calculates the ratio between the terminal voltage value of the thermistor element Rt, which is the measured value, and the voltage value of the power supply 3, and outputs temperature information based on the voltage ratio. In the case of multiple sensors, digital data of the temperature is output as serial data via a parallel interface, and this digital data is serially transmitted via wire or wireless to a processing system such as an external measuring device main body.

[0045] According to this embodiment, even if the power supply voltage value V fluctuates, the ratio of the voltage values ​​does not change, so that highly accurate temperature measurement is possible.

[0046] [Third embodiment] A temperature measuring device according to a third embodiment will be described with reference to Fig. 10. In this embodiment, RFID (Radio Frequency Identification) technology is applied to a composite sensor and a microcomputer serving as a control processing unit to which the composite sensor is connected, and the composite sensor is a remotely controlled temperature measuring device that communicates wirelessly via radio waves and performs information reading and other operations.

[0047] The temperature measuring device 1 of this embodiment includes a circuit block 8, a transmitting / receiving antenna 9, and an IC tag reader 10. The circuit block 8 and the transmitting / receiving antenna 9 are provided on a substrate 11 in the form of a plastic film.

[0048] An IC tag as an RFID tag and a microcomputer serving as a control processing unit are connected to the circuit block 8. A composite sensor in which a thermistor element Rt and a resistor element Rr are connected in series is also connected to the microcomputer. A spirally shaped transmitting / receiving antenna 9 is also connected to the IC tag. In addition, the circuit block 8, the composite sensor, and the transmitting / receiving antenna 9 are arranged on a plastic film-like substrate 11. The IC tag reader 10 is a device for communicating by irradiating and transmitting radio waves to the IC tag.

[0049] The steps for measuring temperature are as follows: first, the IC tag reader 10 irradiates and transmits radio waves toward the IC tag. When the transmitting / receiving antenna 9 receives the radio waves, the IC tag is activated, and the power of the radio waves is used to activate the temperature measurement microcomputer, which converts and outputs temperature information. Next, the IC tag receives the temperature information and transmits it via radio waves from the transmitting / receiving antenna 9 of the IC tag. The IC tag reader 10 receives the temperature information via radio waves. In this way, temperature information can be obtained wirelessly.

[0050] According to the present embodiment as described above, the microcomputer calculates the ratio of the resistance values ​​of the thermistor element Rt and the resistor element Rr or the ratio of the inter-terminal voltage values ​​of the thermistor element Rt and the resistor element Rr, and outputs temperature information, thereby enabling highly accurate temperature measurement.

[0051] Temperature measurement is performed using power supplied by radio waves from the IC tag reader 10, so no battery is required. Also, because no current flows through the composite sensor at all times, the problem of self-heating of the thermistor element Rt is eliminated. The microcomputer transmits temperature information only when power is supplied from the IC tag reader 10 and radio waves are emitted.

[0052] This composite sensor does not require a battery and is thin and lightweight because it can be constructed on a plastic film-like substrate 11. Therefore, it is possible to monitor the temperature by attaching this sensor to sliding parts such as motor bearings and wheels.

[0053] Furthermore, for example, it can be attached to the surface of a patient's body to quickly measure body temperature during a medical examination by a nurse. It is also possible to monitor body temperature without stressing the patient by attaching the IC tag reader 10 to a bed or other location with a composite sensor attached to the patient's body surface. Because it is a wireless, remote temperature measurement device, the patient's body temperature can be monitored even if they move a certain distance. However, if the power supply from the IC tag reader 10 is insufficient for the microcomputer and communications, a separate power source such as a battery can be provided.

[0054] [Temperature Calibration Method] Next, a temperature calibration method according to this embodiment will be described in order to further improve the accuracy of temperature measurement.

[0055] A temperature calibration method according to an embodiment of the present invention includes a composite sensor arranged in the same temperature region and having a thermistor element and a resistor element connected in series, wherein current is passed through the composite sensor to measure the resistance values ​​of the thermistor element and the resistor element or the voltage values ​​between the terminals of the thermistor element and the resistor element, and the measured values ​​are input, and the ratio of the resistance values ​​of the thermistor element and the resistor element or the ratio of the voltage values ​​between the terminals of the thermistor element and the resistor element is calculated from the measured values.

[0056] The calibration is performed by performing fixed-point calibration or comparative calibration at at least two temperatures, recording the data, calculating temperature data from the recorded data, and outputting temperature information based on the resistance ratio of the resistance values ​​or the voltage ratio of the inter-terminal voltage values ​​in a temperature measuring device having an information processing unit, characterized in that the temperature calibration is performed on a composite sensor in which the thermistor element and resistor element are connected in series.

[0057] Furthermore, in order to increase the accuracy between the two fixed points, the applicant has proposed, for example, a temperature calibration device that performs temperature comparison calibration using a reference thermometer and a thermometer to be calibrated (see Japanese Patent Application Laid-Open No. 2022-178910). This conventional temperature calibration device calibrates the temperature of the thermometer to be calibrated by placing the reference thermometer and the thermometer to be calibrated in a temperature calibration block that is maintained at a constant temperature in thermal equilibrium. In this embodiment, the reference thermometer and the thermometer to be calibrated are composite sensors in which a thermistor element and a resistance element are connected in series.

[0058] Therefore, for temperature calibration, the reference composite sensor and the composite sensor to be calibrated are placed in the placement area of ​​the temperature calibration block. The temperature of the temperature calibration block is raised to a predetermined temperature, and the state of thermal equilibrium when this temperature calibration block reaches the predetermined temperature is defined as the calibration temperature.

[0059] Next, data on the relationship between the reference composite sensor and the calibrated composite sensor, that is, the correlation between the temperature and the resistance ratio or voltage ratio between the reference composite sensor and the calibrated composite sensor, is obtained, and a calibration curve between the temperature of the reference composite sensor and the calibrated composite sensor is created to perform temperature calibration.

[0060] In this embodiment, the composite sensor of the thermistor element Rt and the resistor element Rr is placed in a measurement unit at the same temperature, so temperature calibration can be performed taking into account the resistance change of the thermistor element Rt and the temperature fluctuation of the resistor element Rr. Furthermore, by simultaneously calibrating the measurement unit including the thermistor element Rt and the resistor element Rr using a temperature calibration device, high-precision calibration of the thermistor element Rt and the resistor element Rr is possible. Furthermore, even if there are variations unique to the thermistor element Rt and the resistor element Rr in the temperature measurement device, accurate temperature measurement is possible by calibrating each thermistor element Rt and the resistor element Rr or thermistor element Rt and the resistor element Rr for each lot using the temperature calibration device and storing the calibration data in the associated microcomputer or measurement device.

[0061] In this embodiment, the composite sensor is temperature calibrated in one-to-one correspondence with the information processing unit. Therefore, the composite sensor and the information processing unit (microcomputer) are in one-to-one correspondence, and calibration is performed simultaneously with the paired microcomputer. This allows for calibration that takes into account not only variations in the thermistor element Rt and the resistor element Rr, but also variations in the voltage measurement of the microcomputer, thereby achieving improved temperature measurement accuracy. Furthermore, since the composite sensor of the thermistor element Rt and the resistor element Rr and the microcomputer are in one-to-one correspondence and can be calibrated as a set, the data stored in the microcomputer varies depending on the composite thermistor.

[0062] In each of the above embodiments, the temperature information output from the information processing unit can be transmitted to the processing system, for example, via a wired connection or wirelessly via Bluetooth (registered trademark) or the like.

[0063] The present invention is not limited to the configurations of the above-described embodiments, and various modifications are possible within the scope of the invention. Furthermore, the above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0064] DESCRIPTION OF SYMBOLS 1...Temperature measuring device 2...Information processing unit (microcomputer) 3...DC power supply 4...Measuring unit 5...Substrate 6...Electrode layer 7...Wiring 7a...Current source wiring 7b...Voltage measurement wiring 7c...Voltage measurement wiring 7d...Voltage measurement wiring 7e...Current source wiring 8...Circuit block 9...IC tag antenna 10...IC tag reader 11...Plastic film substrate Rt...Thermistor element Rr...Resistance element

Claims

1. A temperature measuring device comprising a composite sensor arranged in the same temperature region and having a thermistor element and a resistive element connected in series, wherein a current is passed through the composite sensor to measure the resistance values ​​of the thermistor element and resistive element or the terminal-to-terminal voltage value of the thermistor element and resistive element, and further comprising an information processing unit which receives the measured value, calculates the resistance value ratio of the thermistor element and resistive element or the terminal-to-terminal voltage ratio of the thermistor element and resistive element from the measured value, and digitally outputs temperature information based on the resistance value ratio or the terminal-to-terminal voltage value ratio.

2. A temperature measuring device comprising a composite sensor arranged in the same temperature region and having a thermistor element and a resistive element connected in series, wherein a current is passed through the composite sensor to measure a terminal voltage value of the thermistor element or resistive element, and wherein the measured value is inputted into an information processing unit which calculates a ratio between the measured value, that is, the terminal voltage value of the thermistor element or resistive element, and a power supply voltage value, and outputs temperature information based on the voltage ratio.

3. The temperature measuring device according to claim 1, characterized in that the composite sensor in which the thermistor element and the resistor element are connected in series measures temperature according to the principle of the four-terminal method.

4. The temperature measuring device according to claim 1 or 2, characterized in that a plurality of the composite sensors are provided, and the plurality of composite sensors are connected to the information processing unit.

5. The temperature measuring device according to claim 1 or 2, characterized in that the temperature information output from the information processing unit is transmitted wirelessly.

6. A temperature measuring device according to claim 1 or 2, characterized in that an IC tag is connected to the information processing unit, and an IC tag reader is provided which supplies power to the IC tag and performs communication therewith.

7. The temperature measuring device according to claim 6, further comprising a separate power source in case the power supply from said IC tag reader is insufficient.

8. A temperature measuring device comprising a composite sensor arranged in the same temperature region and having a thermistor element and a resistive element connected in series, wherein a current is passed through the composite sensor to measure the resistance values ​​of the thermistor element and the resistive element or the terminal-to-terminal voltage value of the thermistor element and the resistive element, the measured value is input, and the device has an information processing unit which calculates from the measured value a ratio of the resistance values ​​of the thermistor element and the resistive element or a ratio of the terminal-to-terminal voltage values ​​of the thermistor element and the resistive element, and outputs temperature information based on the ratio of the resistance values ​​or the ratio of the terminal voltage values, wherein a temperature calibration method is performed using the composite sensor in which the thermistor element and the resistive element are connected in series as a reference composite sensor and a composite sensor to be calibrated.

9. The temperature calibration method according to claim 8, wherein the composite sensor and the information processing unit are temperature calibrated in one-to-one correspondence.

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