KR101922105B1 - Temperature Sensing System using Powerlessly Operating Remote Sensor and Method thereof - Google Patents

Abstract

The present invention relates to a temperature measuring system and a temperature measuring method thereby. The temperature measuring system includes a first sensor for outputting a temperature response signal with frequencies converted according to a temperature change based on incident waves, a second sensor for measuring a temperature and outputting the measured temperature using electric power generated from an ambient electromagnetic field, and a control unit for calibrating a temperature value corresponding to the temperature response signal based on the temperature response signal output from the first sensor and a temperature measured by the second sensor. The present invention generates electric power from the ambient electromagnetic field using the energy harvesting technology and measures and/or outputs a reference value (reference temperature) for calibrating a SAW sensor using the generated electric power, thereby removing the problem that a user has to calibrate the SAW sensor manually according to a change in surrounding physical environments.

Description

TECHNICAL FIELD [0001] The present invention relates to a temperature measurement system using a wireless sensor,

The present invention relates to a temperature measurement system using a non-power wireless sensor and a temperature measurement method using the same, and more particularly, to a temperature measurement system for measuring an abnormal state of a facility by measuring a temperature change of the power facility, .

In the case of large-scale industrial facilities such as industrial power facilities, a failure of the equipment not only causes a large accident but also causes a great economic loss due to the shutdown of the facility. Therefore, it is essential to establish a system that monitors abnormalities of equipment in advance or monitors the failure of equipment in real time at a business site that operates large industrial facilities.

In the case of high-voltage switchboards, over-current protection and arc detection are built in. However, bus-bar, which is a major factor in accidents, has various configurations and is very easy to change. Sensors or other means for preventing the above-mentioned problems are not properly provided.

Especially, in case of high-voltage switchboard booth bar, the temperature sensor should be attached directly to the busbar to prevent fire or explosion due to the temperature rise due to the overcurrent. Since a general wire sensor has a risk of arcing, And a wireless sensor using a battery has a limitation in the maintenance and management such as periodic replacement because the life of the battery is limited.

As a means for solving the above problem, there is a non-power wireless sensor using a surface acoustic wave (SAW) [ Patent Document 1 ]. Particularly, in case of non-power wireless sensor using SAW, since it is a very precise sensor (about 0.1 ° C accuracy in temperature) while ensuring the longest distance performance (~ 3m) among power-free sensors that do not use power at all, It is very suitable as a state detection sensor such as an electric distribution board formed.

However, since the conventional non-power wireless sensor using SAW does not use a power source, when the external physical environment changes (for example, when a new device is installed in the switchboard and the propagation path is changed, Or the like), it is impossible to mount a special circuit or algorithm for automatically calibrating the sensing value, which is a serious problem in commercialization.

On the other hand, energy harvesting refers to the technology of converting the energy that is dumped around, such as vibration / kinetic energy, thermal energy, light energy, and RF energy, into electrical energy.

[Patent Document 1] Korean Patent Publication No. 10-2013-0033385

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an energy harvesting technique for generating electric power from surrounding electromagnetic fields and using it to measure a reference temperature for calibrating a SAW sensor and / The present invention provides a temperature measuring system and a temperature measuring method therefor which fundamentally solves the inconvenience that the SAW sensor has to be calibrated manually in accordance with changes in the surrounding physical environment.

It is another object of the present invention to provide a temperature measuring system and a temperature measuring method for detecting a temperature rise of a high-voltage electric power facility, detecting an anomalous state of the electric power facility in advance, or accurately ascertaining whether or not an abnormality has occurred.

It is another object of the present invention to provide a temperature measurement system capable of wireless measurement in real time using a sensor driven by a non-power source, and a temperature measurement method therefor.

Further, the present invention provides a temperature measurement system and a temperature measurement method by which a SAW sensor can be calibrated without using complicated signal processing or high-performance digital signal processing parts, .

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood from the following description.

A temperature measurement system according to an embodiment of the present invention includes a first sensor that outputs a temperature response signal whose frequency is changed according to a temperature change based on an incident wave; A second sensor for measuring the temperature and outputting the measured temperature using electric power generated from the surrounding electromagnetic field; And a controller for calibrating a temperature value corresponding to the temperature response signal based on the temperature output from the second sensor; . ≪ / RTI >

Wherein the second sensor comprises: a temperature sensor for measuring a temperature; A power generation module for generating electric power from a surrounding electromagnetic field; And a communication module for outputting the temperature measured by the temperature sensor to the control unit using power generated by the power generation module; . ≪ / RTI >

The second sensor is annular and can generate power from an electromagnetic field generated in a power line passing between the annular shapes.

The first sensor can convert the incident wave into a surface acoustic wave, and generate and output a temperature response signal from the surface acoustic wave whose frequency is changed according to the temperature change.

The control unit may calculate a temperature value from the temperature response signal output from the first sensor and calibrate the calculated temperature value using the temperature output from the second sensor.

The controller may calculate a temperature value from the temperature response signal output from the first sensor and calibrate the calculated temperature value using a temperature output from the second sensor as a reference temperature.

The second sensor may output the measured temperature to the control unit at a predetermined cycle.

Wherein the controller calculates a temperature value from the temperature response signal output from the first sensor when the temperature measured by the second sensor is not output and outputs the temperature measured by the second sensor, A temperature value may be calculated from the temperature response signal output from the first sensor, and the temperature value calculated using the temperature output from the second sensor may be calibrated.

The second sensor can measure the temperature using electric power generated from the surrounding electromagnetic field.

The temperature sensor can measure the temperature using the power generated from the power generation module.

The temperature sensor may be a no-power temperature sensor.

The temperature sensor may be a thermocouple type temperature sensor.

The power generation module may include at least one inductive element for generating electric power from the electromagnetic field.

The second sensor may comprise at least one or more power storage elements for storing power generated from the surrounding electromagnetic field.

The power storage device may be a super capacitor.

The communication module may output the measured temperature to the controller using Bluetooth low energy (BLE).

According to another embodiment of the present invention, there is provided a temperature measuring method comprising the steps of: (A) receiving from a first sensor a temperature response signal whose frequency is changed according to a temperature change, based on an incident wave inputted to the first sensor; (B) receiving a temperature measured by the second sensor using power generated by the second sensor; And (C) calibrating a temperature value corresponding to the temperature response signal based on the received temperature; . ≪ / RTI >

The first sensor can convert the incident wave into a surface acoustic wave and generate and output the temperature response signal from the surface acoustic wave whose vibration frequency is changed in accordance with the temperature change.

The step (C) includes: calculating a temperature value using the temperature response signal; And calibrating the calculated temperature value using the received temperature; . ≪ / RTI >

The step (C) includes: calculating a temperature value using the temperature response signal; And calibrating the calculated temperature value using the received temperature as a reference temperature; . ≪ / RTI >

The second sensor may output the measured temperature at a predetermined cycle.

Wherein, in the step (C), when the measured temperature is not received from the second sensor, the temperature value is calculated using the temperature response signal, and when the measured temperature is received from the second sensor, A signal may be used to calculate a temperature value, and the calculated temperature value may be calibrated using the temperature received from the second sensor.

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Quot; a " general inventor ") to fully disclose the scope of the invention.

According to the present invention, the energy harvesting technique can be used to generate power from the surrounding electromagnetic field and use it to measure and / or output a reference temperature for calibrating the SAW sensor, It is possible to provide a temperature measurement system fundamentally solving the inconvenience of manually calibrating the SAW sensor according to the change of the physical environment of the sensor, and a temperature measurement method therefor.

In addition, it is possible to provide a temperature measuring system and a temperature measuring method by which temperature rise of a high-voltage electric power facility can be detected to accurately ascertain whether or not an electric power facility is abnormal.

In addition, it is possible to provide a temperature measurement system capable of wireless measurement in real time using a sensor driven by a non-power source, and a temperature measurement method therefor.

In addition, it is possible to provide a temperature measurement system and a temperature measurement method by which the SAW sensor can be calibrated without complicated signal processing or high-performance digital signal processing components, so that the temperature can be accurately measured while simplifying the calculation.

1 is a view showing an example of a temperature measurement system according to an embodiment of the present invention.
2 is a view showing a configuration of a second sensor of a temperature measurement system according to an embodiment of the present invention.
3 is a diagram showing a configuration of a second sensor of a temperature measurement system according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a configuration and a signal flow of a temperature measurement system according to an embodiment of the present invention.
5 is a detailed view illustrating a signal flow of a temperature measurement system according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating a temperature measurement method according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

Various features of the invention disclosed in the claims may be better understood in view of the drawings and detailed description. The devices, methods, processes and various embodiments disclosed in the specification are provided for illustration. The disclosed structural and functional features are intended to enable a person skilled in the art to practice various embodiments and are not intended to limit the scope of the invention. The terms and phrases disclosed are intended to facilitate understanding of the various features of the disclosed invention and are not intended to limit the scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a temperature measuring system and a temperature measuring method according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a view showing an example of a temperature measuring system according to an embodiment of the present invention, and FIG. 2 is a view showing a shape of a second sensor of a temperature measuring system according to an embodiment of the present invention .

1 and 2, the temperature measuring system 1 according to the present embodiment may include a sensor unit 10 and a control unit 20. The sensor unit 10 may include a first sensor 100 and a second sensor 200.

The sensor unit 10 is provided with various facilities for performing power management such as power generation, water distribution, and the like, for example, a high voltage circuit breaker, a high voltage power line, a switchboard booth bar, a transformer, Measurement object "). The sensor unit 10 may measure the temperature of the measured object and transmit the measured temperature to the control unit 20. At this time, it is preferable that the measured temperature is transmitted using wireless communication.

An alternating current may flow through the object to be measured, and an electromagnetic field may be generated around the object to be measured by the alternating current.

The first sensor 100 and the second sensor 200 may be provided together in the sensor unit 10 or they may be separated from each other independently.

The shapes of the sensor unit 10, the first sensor 100 and the second sensor 200 are not specified and may have various shapes depending on the purpose of use such as a cylindrical shape, an annular shape, have.

For example, in the case of the second sensor 200 having an annular shape, the second sensor 200 may be provided on the object to be measured so that the object to be measured passes through between the annular shapes. The second sensor 200 may generate electric power using an electromagnetic field generated around the object to be measured.

The first sensor 100 can receive an incident wave (hereinafter referred to as "call signal") transmitted from the control unit 20. [ The method by which the control unit 20 transmits the paging signal is not specified, and for example, it can be periodically transmitted at regular intervals, and the manager can manually transmit the paging signal. In addition, it can be sent out in an appropriate manner depending on the purpose and environment.

The first sensor 100 can reverse-convert the call signal to a surface acoustic wave (SAW) using a SAW transponder provided therein.

After the first sensor 100 reflects the temperature change of the measured object on the surface acoustic wave and converts the temperature change to a SAW echo signal (hereinafter referred to as a "temperature response signal"), .

Meanwhile, the second sensor 200 can measure the temperature of the measured object using the temperature sensor 210 provided therein. The second sensor 200 generates electric power by using an electromagnetic field generated around the subject and outputs the temperature measured by the temperature sensor 210 to the control unit 20 at predetermined time intervals using the generated electric power Can be output.

The control unit 20 receives the temperature response signal output from the first sensor 100 and can calculate the temperature value using the temperature response signal. Also, the controller 20 may calibrate the calculated temperature by using the temperature output from the second sensor 200 as a reference temperature at predetermined intervals.

That is, the controller 20 does not output the temperature measured by the second sensor 200, and when the measured temperature is not received, the controller 20 can calculate the temperature value from the temperature response signal. On the other hand, when the measured temperature is received by the second sensor 200, a temperature value is calculated from the temperature response signal, and the temperature output from the second sensor 200 is compared with a reference temperature ), And the calculated temperature value can be corrected. Further, the temperature value can be calculated by reflecting the calibration result when calculating the temperature value thereafter.

As described above, in the temperature measuring system 1 according to the present embodiment, in the process of measuring the temperature of the measured object through information exchange between the sensor unit 10 and the control unit 20, There is an advantage that the temperature of the object to be measured can be measured with wireless free of charge.

In addition, there is an advantage that the disadvantage of the non-power wireless sensor using the SAW sensitive to external physical environment change can be solved by automatically calibrating the temperature value calculated every predetermined time using the reference value.

Further, since the SAW sensor can be calibrated without using complicated signal processing or high-performance digital signal processing parts, there is an advantage that the temperature of the measuring object can be accurately measured while simplifying the calculation.

3 is a diagram showing a configuration of a second sensor 200 of the temperature measurement system 1 according to an embodiment of the present invention.

3, the second sensor 200 according to the present embodiment includes a temperature sensor 210, a power generation module 220, a converter 230, a power storage device 240, and a communication module 250 .

The type of the temperature sensor 210 is not specified and includes all means capable of measuring the temperature of the measured object in addition to the predetermined sensor. For example, the temperature sensor 210 may be a sensor requiring power for temperature measurement. At this time, the power required by the temperature sensor 210 can be generated and supplied from the power generation module 220. Meanwhile, the temperature sensor 210 may be a sensor capable of measuring the temperature in a non-power source without requiring power. Also, the temperature sensor 210 may be a thermocouple type temperature sensor. The predetermined time at which the temperature sensor 210 measures the temperature of the measured object is not specified. For example, the predetermined time may be measured continuously or may be measured at predetermined intervals.

The power generation module 220 can generate electric power using an electromagnetic field generated around the measured object. Meanwhile, the power generation module 220 may include at least one inductive element for generating electric power from the electromagnetic field.

The power generated in the power generation module 220 may be converted to DC in the converter 230 and stored in the power storage element 240. [ At this time, the power storage device 240 preferably uses a super capacitor.

The supercapacitor is a capacitor having a very large capacitance, and can store power generated by the power generation module 220 using a simple phenomenon of ion transfer to the electrolyte interface with the electrode or a charging phenomenon by surface chemical reaction. Super capacitors are capable of rapid charge / discharge, have high charge / discharge efficiency and semi-permanent lifetime. Accordingly, when the power storage device 240 is implemented using the supercapacitor, the power generated from the power generation module 220 can be more efficiently stored, and power can be effectively supplied to the communication module 250 and the like .

On the other hand, although it is not so limited, power generated from a high voltage power line or an electromagnetic field around a switchboard bus bar is very small (measured by 0.5 μW in an experimental example according to an embodiment of the present invention, but not limited thereto) The power stored in the power storage device 240 is supplied to the temperature sensor 210 and / or the communication module 250 at a predetermined time, It is preferable to output a temperature to the control unit 20. [

At this time, the predetermined time for outputting the measured temperature is not specified, and the intensity of the electric current flowing in the measured object, the intensity of the electromagnetic field generated in the measured object, the distance between the measured object and the sensor unit 10, 220, the allowable sensing error range, and the like. Preferably, it may be set to a time having a predetermined period. More preferably, in consideration of the intensity of an electromagnetic field generated around a general power line through which a 60 Hz alternating current flows, the temperature may be set so as to output a temperature measured periodically four or more times.

The communication technology used to output the temperature measured by the temperature sensor 210 in the communication module 250 is not specified. For example, the temperature measured using the Bluetooth low energy (BLE) can do. The low-power Bluetooth has an operation period of several milliseconds (ms) and most of the time is a sleep mode, which has a very small power consumption. Accordingly, there is an advantage that the second sensor 200 having a very high power efficiency can be realized.

FIG. 4 is a diagram showing the configuration and signal flow of the temperature measurement system 1 according to the embodiment of the present invention, and FIG. 5 is a diagram showing the flow of signals of the temperature measurement system 1 according to the embodiment of the present invention Fig. In the following description, the same elements as those described above will not be described.

Referring to FIGS. 4 and 5, the first sensor 100 according to the present embodiment uses a SAW transponder provided therein to convert a paging signal received by the antenna 110 into a surface acoustic wave reverse- Can be converted. The converted surface acoustic waves are propagated in both directions of the piezoelectric substrate.

At this time, the elastic energy of the surface acoustic wave becomes maximum at the resonance frequency, and the resonance frequency can be changed by the surrounding temperature. Specifically, the length of the piezoelectric substrate of the SAW transponder is thermally expanded due to the ambient temperature, which can change the group velocity of the surface acoustic wave. The change of the group velocity of the surface acoustic wave can induce the change of the resonance frequency of the surface acoustic wave.

The elastic energy of the surface acoustic wave whose resonance frequency has been changed can be converted into a radio wave energy (temperature response signal) including the resonance frequency information by the piezoelectric effect. The antenna 110 may output the converted radio wave energy to the controller 20.

That is, the antenna 110 serves to receive the call signal sent from the control unit 20 and to output the temperature response signal to the control unit 20.

Since the first sensor 100 is composed of only the antenna 110 and the SAW temperature sensor, the structure is very simple and can be manufactured in a small size and light weight.

On the other hand, the second sensor 200 measures the temperature of the measured object and outputs the measured temperature to the control unit 20. Specifically, the temperature of the measured object can be measured using the temperature sensor 210. [ At this time, it is preferable that the temperature value of the temperature sensor 210 is not affected by the external physical environment, or the change is smaller than that of the first sensor 100 even if the sensing value is influenced. The communication module 250 may output the temperature measured by the temperature sensor 210 to the control unit 20 at predetermined intervals.

The control unit 20 can calculate the temperature value of the measured object by analyzing the temperature response signal. Specifically, the change in temperature causes a change in the resonance frequency of the surface acoustic wave in addition to the change in the speed of the surface acoustic wave. Since the temperature response signal includes information about the resonance frequency of the surface acoustic wave, It is possible to calculate the temperature value of the measured object by analyzing the frequency change of the surface acoustic wave from the signal.

Meanwhile, the control unit 20 may calibrate the calculated temperature using the temperature output from the second sensor 200 as a reference temperature. The method of calibration is not specified, and can be calibrated, for example, using the difference between the calculated temperature value and the reference value. Specifically, when the calculated temperature value is 6 ° C and the reference value is 10 ° C, the temperature value can be calculated by performing calibration and adding 4 ° C later in calculating the temperature value. In addition, calibration can be carried out variously according to the purpose of use and environment, such as a method of using an average value, a method of performing calibration only when the tolerance exceeds an allowable range.

6 is a flowchart showing a temperature measuring method according to another embodiment of the present invention. In the following description, the same elements as those described above will not be described.

Referring to FIG. 6, the temperature measuring method according to the present embodiment includes receiving, from the first sensor 100, a temperature response signal whose frequency has changed according to a temperature change, based on an incident wave input to the first sensor 100 A step S510 of receiving the temperature measured by the second sensor 200 using the power generated by the second sensor 200 and a step S520 of receiving the temperature measured by the second sensor 200 (S530) calculating a temperature value using the temperature response signal, and calculating a temperature value using the temperature response signal when the measured temperature is received from the second sensor 200, And correcting the calculated temperature value using the temperature received from the sensor 200 (S540).

In step S540, the calculated temperature value can be calibrated using the received temperature as a reference value.

The temperature measuring system and the temperature measuring method according to the present invention according to the present invention generate power from the surrounding electromagnetic field using the energy harvesting technique and use the reference value to calibrate the SAW sensor temperature of the SAW sensor can be measured and / or output, so that the inconvenience of manually calibrating the SAW sensor according to the change of the surrounding physical environment is radically solved.

Further, there is an effect that it is possible to accurately ascertain whether or not an abnormality occurs in the electric power facility by detecting the temperature rise of the high-voltage electric power facility.

In addition, there is an effect that wireless measurement can be performed in real time using a sensor driven by a non-power source.

In addition, since the SAW sensor can be calibrated without using complicated signal processing or high-performance digital signal processing parts, the temperature can be accurately measured while simplifying the calculation.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed herein are for the purpose of describing, not limiting, the technical spirit of the present invention, and the scope of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of the same should be understood as being included in the scope of the present invention.

1: Temperature measurement system 10: Sensor unit
20: control unit 100: first sensor
110: antenna 200: second sensor
210: temperature sensor 220: power generation module
230: converter 240: power storage element
250: Communication module

Claims (22)

A first sensor for converting an incident wave into a surface acoustic wave and outputting a temperature response signal generated from the surface acoustic wave whose frequency is changed according to a temperature change; Wherein the temperature response signal includes information on the changed frequency,
A second sensor for measuring the temperature and outputting the measured temperature using electric power generated from the surrounding electromagnetic field; And
A control unit for calibrating a temperature value corresponding to the temperature response signal based on the temperature output from the second sensor;
/ RTI >
Temperature measurement system.
The method according to claim 1,
Wherein the second sensor comprises:
A temperature sensor for measuring temperature;
A power generation module for generating electric power from a surrounding electromagnetic field; And
A communication module for outputting the temperature measured by the temperature sensor to the control unit using the power generated by the power generation module;
/ RTI >
Temperature measurement system.
The method according to claim 1,
Wherein the second sensor comprises:
Shaped,
And generating electric power from an electromagnetic field generated in a power line penetrating between the annular shapes,
Temperature measurement system.
delete The method according to claim 1,
Wherein,
Calculating a temperature value from the temperature response signal output from the first sensor,
And calibrating the calculated temperature value using the temperature output from the second sensor,
Temperature measurement system.
The method according to claim 1,
Wherein,
Calculating a temperature value from the temperature response signal output from the first sensor,
And a second temperature sensor for detecting a temperature of the second sensor,
Temperature measurement system.
The method according to claim 1,
Wherein the second sensor comprises:
And outputting the measured temperature to the control unit at a predetermined cycle,
Temperature measurement system.
The method according to claim 1,
Wherein,
When the temperature measured by the second sensor is not output,
Calculating a temperature value from the temperature response signal output from the first sensor,
When the temperature measured by the second sensor is outputted,
Calculating a temperature value from the temperature response signal output from the first sensor,
A temperature sensor for detecting a temperature of the first sensor,
Temperature measurement system.
The method according to claim 1,
Wherein the second sensor comprises:
Measuring the temperature using power generated from the surrounding electromagnetic field,
Temperature measurement system.
3. The method of claim 2,
The temperature sensor includes:
And a temperature measuring unit for measuring temperature using power generated from the power generation module,
Temperature measurement system.
3. The method of claim 2,
The temperature sensor includes:
As a non-powered temperature sensor,
Temperature measurement system.
3. The method of claim 2,
The temperature sensor includes:
As a thermocouple type temperature sensor,
Temperature measurement system.
3. The method of claim 2,
The power generation module includes:
And at least one inductive element for generating electrical power from the electromagnetic field.
Temperature measurement system.
The method according to claim 1,
Wherein the second sensor comprises:
And at least one power storage element for storing power generated from the surrounding electromagnetic field.
Temperature measurement system.
15. The method of claim 14,
The power storage device includes:
As super capacitors,
Temperature measurement system.
3. The method of claim 2,
The communication module includes:
And outputting the measured temperature to the controller using Bluetooth low energy (BLE)
Temperature measurement system.
(A) receiving from a first sensor a temperature response signal generated from a surface acoustic wave converted from an incident wave input to the first sensor and having a frequency changed according to a temperature change; Wherein the temperature response signal includes information on the changed frequency,
(B) receiving a temperature measured by the second sensor using power generated by the second sensor; And
(C) calibrating a temperature value corresponding to the temperature response signal based on the received temperature;
/ RTI >
Method of measuring temperature.
delete 18. The method of claim 17,
The step (C)
Calculating a temperature value using the temperature response signal; And
Calibrating the calculated temperature value using the received temperature;
/ RTI >
Method of measuring temperature.
18. The method of claim 17,
The step (C)
Calculating a temperature value using the temperature response signal; And
Calibrating the calculated temperature value with the received temperature as a reference temperature;
/ RTI >
Method of measuring temperature.
18. The method of claim 17,
Wherein the second sensor comprises:
And outputting the measured temperature at a predetermined cycle,
Method of measuring temperature.
18. The method of claim 17,
In the step (C)
If the measured temperature from the second sensor is not received,
Calculates a temperature value using the temperature response signal,
When the measured temperature is received from the second sensor,
Calculates a temperature value using the temperature response signal,
And calibrating the calculated temperature value using the temperature received from the second sensor,
Method of measuring temperature.

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