JP2017072479A - Temperature measurement apparatus and temperature measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensor, a temperature measurement apparatus and a temperature measurement method which have a simple structure, can reduce an apparatus cost, can improve measurement accuracy, and are suitable for measurement air temperature in the outdoor.SOLUTION: A temperature sensor 1 has a plurality of thermocouples 2, 3 and 4 having spheres 2a, 3a and 4a as temperature sensitive portions, and the respective temperature sensitive portions of the thermocouples are spheres having different volumes, and are arranged at predetermined intervals. A temperature measurement apparatus 10 includes temperature calculation means 11 which converts each of electromotive forces of the plurality of thermocouples 2, 3 and 4 and calculates each of the temperatures, and correction temperature calculation means 12 which calculates a correction temperature 12a based on each of the temperatures calculated by the temperature calculation means, and the correction temperature calculation means 12 calculates the correction temperature 12a based on temperature gradients of each of the temperatures calculated based on the diameter of the spheres of the temperature sensitive portions by the temperature calculation means 11, and displays the calculated correction temperature on temperature display means 13.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a temperature sensor, a temperature measuring device, and a temperature measuring method for measuring air temperature and the like, and in particular, a temperature sensor having a plurality of thermocouples, a temperature measuring device and a temperature with improved measurement accuracy using the temperature sensor. It relates to a measurement method.

  Since a general temperature measurement apparatus performs measurement in various applications and under various environmental conditions, the measured data may vary under the influence of various environments. For example, in outdoor temperature measurement, since a thermosensitive part of a thermometer is generally heated by the influence of solar radiation, measurement with a shelter for shielding solar radiation is performed. However, since the shelter of the radiation shield itself warms up during the day, there is an influence of infrared radiation incident on the thermosensitive part of the thermometer from the shelter, and the measured value of the temperature increases by 3 to 4 ° C at maximum in natural ventilation. It is known. On the other hand, it is known that the measured value of the temperature is underestimated because the shelter is cooled by radiation cooling at night.

  This error is generally inaccurate because the accumulated maximum temperature used in plant physiology, growth analysis, etc. is accumulated in the agricultural field in addition to the problem that the maximum and minimum temperatures measured are generally inaccurate. Problem arises. For this reason, high-precision outdoor temperature measurement requires measurement with a forced draft tube that reduces the influence of radiation by ventilating the shelter with a fan, blower, or the like. And the influence of radiation is suppressed by arranging a thermometer in the center of the forced draft tube.

  However, since these temperature measuring devices require electric power for driving a fan, a blower or the like, a power source is required for temperature observation. When commercial power sources such as mountainous areas cannot be secured, it is necessary to install solar panels and batteries in order to drive the fans at all times. For this reason, the installation space of the necessary equipment becomes a problem, the configuration is complicated and the cost is high, and it can be said that it is sufficiently popular in the field of temperature measurement for agriculture such as horticultural facilities and cultivation research. Absent. Furthermore, in the conventional thermometer, the shape of the sensitive part is a cylinder, a flat ellipsoid, or a flat plate, and the characteristics of the air flow around the sensitive part change due to changes in the wind direction. Difficult to get.

  In addition, as a conventional temperature measuring device for measuring this type of temperature, there is a field server for long-term humidity measurement, and this device includes a measurement chamber, an outside air suction chamber, an outside air intake preparatory chamber, and a filter portion with low hygroscopicity. When the electric fan in the outside air intake chamber rotates, outside air is sucked in from the two outside air intake holes of the outside air intake preparatory chamber, passes through the filter section, and the outside air is introduced into the measurement chamber, and the internal humidity sensor Then, it passes through the internal temperature sensor and is discharged to the outside through the outer peripheral gap of the upper lid, so that the air flow flows upward from below (see, for example, Patent Document 1).

  Furthermore, as a conventional device for measuring this kind of temperature, there is a physical quantity sensor device that detects a physical quantity, and this device includes a plurality of temperature sensors for detecting the temperature of a sensor chip, The circuit unit for correcting the physical quantity based on the detected temperature is provided to improve the accuracy of temperature correction (see, for example, Patent Document 2).

JP 2008-64591 A JP 2005-257623 A

  By the way, in the temperature measuring device having the above structure, the outside air introduced by the electric fan passes through the filter portion, the outside air suction chamber, and the measurement chamber from the outside air intake preliminary chamber and is discharged to the outside. There was a problem of high costs. Also, since the outside air taken into the outside air taking-in chamber is taken into a wide space from the two outside air taking holes, the air inside the space stays and the temperature distribution is not constant, and the outside air flow is stable. There is a problem that the measurement accuracy of temperature and humidity may be affected. Furthermore, the introduction path of the outside air is complicated, and the electric fan must have a high output.

  Further, the physical quantity sensor device estimates the average value of the temperatures detected by the temperature sensors 9a to 9d as the temperature near the center of the sensor chip 5, or gives a predetermined weight to the temperatures detected by the temperature sensors 9a to 9d. It is calculated by doing. For this reason, this physical quantity sensor device has a large difference between the estimated temperature or the calculated temperature and the true temperature, and is not suitable for outdoor temperature measurement.

The present invention has been made in view of such problems, and the object of the present invention is to simplify the configuration, reduce the device cost, improve the measurement accuracy, and improve the general temperature. An object of the present invention is to provide a temperature sensor, a temperature measuring device, and a temperature measuring method that can be used for various applications as a measuring device and are not easily affected by the environment.
It is another object of the present invention to provide a temperature sensor, a temperature measuring device, and a temperature measuring method suitable for measuring an outdoor temperature such as paddy fields and field fields that are easily affected by solar radiation and wind.

  In order to achieve the above object, the temperature sensor according to the present invention includes a plurality of thermocouples each having a temperature sensing portion, and each temperature sensing portion of the thermocouple has a different volume. The temperature sensing unit is a sphere. Further, the plurality of thermocouples are formed integrally with each of the temperature sensing portions being arranged at a predetermined interval and by collecting the end portions of the thermocouple on the side opposite to the temperature sensing portion. The plurality of thermocouples are preferably arranged at equal intervals on one virtual circumference.

The temperature sensor of the present invention configured as described above has a phenomenon that when the thermosensitive part of the thermocouple has a different volume, there is a phenomenon that the electromotive force (temperature) generated varies depending on the environment and the plurality of different temperatures. It was made based on the new knowledge that it is possible to calculate a correction temperature close to one true temperature by correcting, and by making a plurality of thermocouples with different volumes of the temperature sensing part into one temperature sensor A configuration capable of more accurately and easily obtaining a plurality of temperature data having different generated electromotive forces, and easily obtaining a correction temperature close to the true temperature from the plurality of temperature data by subsequent data processing; It is a thing.
In addition, the temperature sensor of the present invention can reduce the number of parts and facilitate assembly of the apparatus and installation outdoors.

  As a preferable specific aspect of the temperature sensor according to the present invention, it is preferable that the plurality of thermocouples is three to five. Furthermore, it is preferable that the plurality of thermocouples are covered with a stainless steel pipe leaving the temperature sensitive part. According to this configuration, three to five thermocouples can be arranged at equal intervals on one virtual circumference, and the influence of natural wind can be suppressed. If the coating is made while leaving the portion, durability against wind and rain can be improved.

  A temperature measurement device according to the present invention includes any one of the temperature sensors described above, and includes a temperature calculation unit that converts each electromotive force of the plurality of thermocouples to calculate each temperature, and the temperature calculation unit. Correction temperature calculation means for calculating one correction temperature based on each of the calculated temperatures. According to this configuration, a plurality of temperatures can be calculated by the temperature calculation means using a plurality of thermocouples of the temperature sensor, and one correction temperature is calculated based on each temperature calculated by the correction temperature calculation means. Therefore, it is possible to calculate a correction temperature close to the true temperature while suppressing the influence of radiation applied to each thermocouple.

As another aspect of the temperature measuring device according to the present invention, a temperature calculating unit that includes a temperature sensor in which the temperature sensing unit is a sphere, converts each electromotive force of the plurality of thermocouples, and calculates each temperature; Correction temperature calculation means for calculating one correction temperature based on each temperature calculated by the temperature calculation means, and the correction temperature calculation means has a diameter based on the diameter of each sphere of the temperature sensing unit. A power average value, a temperature average value of each temperature of the temperature sensing unit, and a calculation unit that calculates a temperature gradient based on the diameter of each sphere, the power average value of the diameter, the temperature, and the temperature average value. The correction temperature calculation means includes a correction temperature calculation unit that calculates the correction temperature based on the temperature average value, the diameter power average value, and the temperature gradient. It is said.
According to this configuration, the correction temperature calculation means calculates the correction temperature based on the temperature gradient of each temperature calculated based on a plurality of thermocouples having different diameters of the spheres of the temperature sensor of the temperature sensor. It is possible to calculate a correction temperature close to the true temperature while suppressing the influence of radiation.

Further, in the temperature measuring device, the three parts of the correction thermometer set the correction temperature as Ta, the temperature average value of each temperature calculated by the temperature calculation means is Ts, and each sphere of the temperature sensing part is The correction temperature Ta is calculated from the equation Ts−Ta = B × D, where D is the average power of diameters based on the diameter and B is the temperature gradient.
According to this configuration, based on the difference in the amount of radiation received by the plurality of thermocouple temperature sensing units, based on the average value of each temperature measured by the thermocouple temperature sensing unit and the diameter of each sphere of the thermocouple temperature sensing unit. The temperature gradient can be calculated from the power average value of the diameters, and a corrected temperature close to the true temperature can be calculated based on the theory of heat transfer.

  And it is preferable that the said temperature measurement apparatus is provided with the display means which displays the said correction temperature. According to this configuration, the correction temperature close to the calculated true temperature can be displayed on the display means, and the correction temperature can be quickly known in a paddy field, a field or the like where the temperature measuring device is installed.

A temperature measurement method according to the present invention is a temperature measurement method using any one of the temperature sensors described above, and measures each electromotive force of the plurality of thermocouples and converts each electromotive force into each temperature. One correction temperature is calculated based on the converted temperatures.
According to another aspect of the temperature measurement method of the present invention, the temperature sensing unit includes a temperature sensor having a spherical shape, and measures each electromotive force of the plurality of thermocouples to convert each electromotive force into each temperature. A diameter power average value based on a diameter of each sphere of the temperature sensing part, a temperature average value of each temperature of the temperature sensing part, a diameter of each sphere, a diameter power mean value, and each temperature; The correction temperature is calculated based on a temperature gradient based on the temperature average value. Further, when the corrected temperature is Ta, the temperature average value of each temperature is Ts, the diameter power average value based on the diameter of each sphere of the temperature sensing portion is D, and the temperature gradient is B, the equation Ts−Ta The correction temperature Ta is calculated from B × D.
According to this configuration, each electromotive force of a plurality of thermocouples is converted into each temperature, and the correction temperature is calculated based on each converted temperature. Therefore, the true temperature is obtained based on the temperature gradient of each temperature. Close temperature can be measured.

  The temperature sensor, temperature measuring apparatus, and temperature measuring method of the present invention enable accurate temperature measurement using a plurality of temperatures simultaneously measured by a plurality of thermocouples having different temperature sensing part volumes. That is, the influence of radiation applied to a plurality of temperature sensing parts having different volumes can be asymptotically removed in calculation, and the temperature can be accurately measured without providing radiation shielding. Further, it is suitable for outdoor temperature measurement, consumes less power, can be driven without a commercial power supply, and does not require facilities such as a solar cell panel and a battery.

The perspective view of the state which installed one Embodiment of the temperature measuring device which concerns on this invention in a paddy field, a field, etc. FIG. (A) is a front view of one thermocouple used with the temperature measuring apparatus shown in FIG. 1, (b) is a perspective view of a state in which three thermocouples are assembled. (A) is a control block diagram which shows the principal part structure of the temperature measuring device of this embodiment, (b) is a control block diagram which shows the detail of (a). The image figure of how to obtain | require the air temperature by the temperature measuring apparatus using several temperature sensors. An image of how to find the temperature based on the theory of heat transfer. The control flowchart which shows operation | movement description of the temperature measuring device of this embodiment. The graph which shows the temperature data calculated based on the theory of heat transfer. The graph which shows the relationship between the temperature data computed based on the theory of heat transfer, and the measured value of a standard thermometer. The principal part perspective view of other embodiment of the temperature sensor which concerns on this invention. The schematic diagram which looked at the temperature sensor of FIG. 9 from the plane direction. The principal part perspective view of the modification of the temperature sensing part of a temperature sensor.

  Hereinafter, an embodiment of a temperature measuring device using a temperature sensor according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a state in which the temperature measuring device according to the present embodiment is installed in a paddy field, a field, etc., FIG. 2A is a front view of one thermocouple used in the temperature measuring device of FIG. 2 (b) is a perspective view of a temperature sensor in which three thermocouples of FIG. 2 (a) are assembled, and FIG. 3 (a) is a control block showing the main configuration of the temperature measuring device shown in FIGS. FIG. 4B is a detailed control block diagram of FIG.

  1 to 3, the temperature sensor 1 according to the present embodiment includes a thermocouple having a plurality of temperature sensing units, and in this embodiment, includes three thermocouples 2, 3, and 4. The three thermocouples 2, 3 and 4 are formed of thin wires having a wire diameter of about 0.1 mm, for example, the tips of copper-constantan thin wires are welded, and the weld portions have different diameters. Stainless steel spheres 2a, 3a, 4a are fixed in a covered state.

  In this embodiment, spheres 2a, 3a, and 4a having diameters of 0.25 mm, 1 mm, and 4 mm are fixed to the welds at the tips of the thermocouples 2, 3, and 4 by welding or the like. These spheres 2a, 3a and 4a constitute the temperature sensitive parts of the thermocouples 2, 3 and 4, and the diameter and volume of the temperature sensitive parts are different from each other. For this reason, the three thermocouples 2, 3, and 4 are configured to have different surface areas of the temperature sensing portion and different effects of heat radiation. The wire diameter of the thermocouple is not limited to 0.1 mm, and a thinner wire wire or a thick wire may be used. The sphere is not limited to stainless steel, but may be composed of other metals such as brass, or a thermocouple welded portion processed into a sphere.

  The three thermocouples 2, 3, and 4 are formed of stainless steel tubes having a diameter of about 2 mm and an inner diameter of about 1 mm, and are bent so that the vertical portion is 75 mm, the horizontal portion is 75 mm, and the vertical portion is about 75 mm. The three support pipes 2b, 3b and 4b are covered and inserted. The three support pipes 2b, 3b, 4b are arranged such that the lower vertical parts are gathered by the grip part 5, the horizontal parts are fixed at intervals of 120 °, the upper vertical parts are separated by about 130 mm, etc. The spheres 2a, 3a, 4a, which are fixed so as to be spaced and constitute the temperature sensing portion, are arranged at equal intervals on one virtual circumference.

  The three thermocouples 2, 3 and 4 are inserted into the three support tubes 2b, 3b and 4b with the temperature sensitive portions covered, and are fixed with the spheres 2a, 3a and 4a covering the welded portions at the ends. Then, two wires below the thermocouple protrude from the lower ends of the three support tubes 2b, 3b, and 4b, and the respective wires are connected to the compensating conductors 2c, 3c, and 4c. Each compensation conducting wire 2c, 3c, 4c is connected to a connection wire 6 and is configured to output three temperature data via the connection wire 6. As described above, the plurality of thermocouples 2, 3, 4 are configured as a single body in which the spheres 2 a, 3 a, 4 a constituting the temperature sensing part are arranged at a predetermined interval by the grip part 5.

  A temperature measuring device 10 having a temperature sensor 1 in which a plurality of thermocouples 2, 3, 4 configured as described above is integrated is fixed to an upper portion of an observation pole 7 installed on the ground G such as a paddy field or a field. The connecting wire 6 connected to the compensating conductors 2c, 3c, 4c fixed to the arm 8 and connected to the plurality of thermocouples 2, 3, 4 is taken into the data logger 9 fixed to the pole 7. The arm 8 is not always necessary, and the temperature sensor 1 may be directly fixed to the pole 7. The thermocouples 2, 3, and 4 are installed so that the height is about 1.5 to 2 m from the ground.

  The temperature measuring device 10 is basically composed of a temperature sensor 1 having a plurality of thermocouples 2, 3, 4, compensating conductors 2 c, 3 c, 4 c, connection wires 6, and a data logger 9, and consumes power. Is the data logger 9 only, and can be continuously observed for a long time with a simple power source such as a dry battery. For this reason, a commercial power source is not required to measure the temperature, and a solar cell panel and a battery for power storage are not required, and the configuration is extremely simple. Therefore, the cost of the temperature measuring device 10 can be reduced. In addition, since the thermocouples 2, 3, and 4 can reduce the volume of the temperature sensing portion, the influence of radiation can be reduced. Furthermore, since the spheres 2a, 3a, 4a are covered and fixed to the welded portions at the tips of the three thermocouples 2, 3, 4 constituting the temperature sensing part of the temperature sensor 1, the temperature sensor 1 is exposed to wind and rain. Even if it is done, breakage of the welded portion can be prevented.

  The temperature sensing part of the temperature sensor 1 is the spheres 2a, 3a, 4a. If the radiation amount per unit surface area received by the temperature sensing part of the temperature sensor 1 is R, the change in R (theoretically similar) The aim is to minimize and prevent the flow characteristics from changing due to the wind entry angle (although there is no difference in the value of R). In addition, in the three-point arrangement, it is preferable to arrange such that the influence of wind interception by each thermocouple on other thermocouples can be reduced as much as possible with respect to the wind direction changing according to the season and time. Specifically, it is preferable that the thermocouple having a sphere having a larger diameter is arranged so that the distance becomes larger, and the arrangement is a right triangle having an integer ratio (for example, 3: 4: 5) that is easy to process. This embodiment will be described later.

As shown in FIG. 3, the temperature measuring apparatus 10 of the present embodiment includes a temperature sensor 1 including three thermocouples 2, 3, 4 having spheres 2 a, 3 a, 4 a that constitute a temperature sensing unit, and 3 A temperature calculation means 11 for calculating each temperature by converting each electromotive force of the thermocouple of the book, and spheres (temperature sensing parts) 2a and 3a of the three thermocouples 2, 3 and 4 calculated by the temperature calculation means 11 , 4a, a correction temperature calculation unit 12 that calculates a correction temperature based on each temperature calculated from the electromotive force of 4a, and a temperature display unit 13 that displays the correction temperature 12a calculated by the correction temperature calculation unit 22. The The diameters (d ₁ , d ₂ ...) Of the spheres (2 a, 3 a, 4 a) constituting the temperature sensing part are inputted from the temperature sensing part diameter input part 14 to the corrected temperature calculation means 12. Note that the diameter of the sphere is not limited to that input to the correction temperature calculation unit 12, but may be input to the temperature calculation unit 11 or the like.

  The electromotive forces 2d, 3d, and 4d output from the thermocouple temperature sensing parts (spheres) 2a, 3a, and 4a of the temperature sensor 1 are input to the temperature calculation unit 11 and converted into the temperatures 11a, 11b, and 11c. The converted temperatures 11a, 11b, and 11c are input to the correction temperature calculation means 12, and one correction temperature 12a that suppresses the influence of radiation applied to the three thermocouples 2, 3, and 4 of the temperature sensor 1 is obtained. It is calculated and displayed on the temperature display means 13. More specifically, as shown in FIG. 3B, the correction temperature calculation means 12 includes a diameter power average value (D), a temperature average value (Ts), a temperature gradient (B) calculation unit 12A, and a correction temperature calculation unit 12B. The diameter power average value, the temperature average value, and the temperature gradient calculation unit 12A calculate a diameter power average value 12b based on the diameters of the spheres 2a, 3a, and 4a, and output each temperature 11a, A temperature average value 12c is calculated from 11b and 11c, and a temperature gradient 12d is calculated. The corrected temperature calculation unit 12B calculates the corrected temperature 12a from the diameter power average value 12b, the temperature average value 12c, and the temperature gradient 12d. In addition, each temperature 11a, 11b, 11c output from the temperature calculation means 11 and the diameter data from the temperature sensing part diameter input part 14 are supplied to the personal computer 16 by the storage device 15 or wireless LAN etc., and a correction temperature is calculated. You may comprise as follows. In this case, the diameter of the sphere is input to the personal computer 16 from the temperature sensing unit diameter input unit 14.

  The temperature measuring operation of the temperature measuring apparatus 10 including the temperature sensor 1 of the present embodiment configured as described above will be described below. In this temperature measuring apparatus 10, a plurality of thermocouples 2, 3, and 4 of the temperature sensor 1 are used, and the diameters of the spheres 2a, 3a, and 4a at the tip that constitute the temperature sensing unit are configured to be different. The air temperature is measured simultaneously with the thermocouples, and as shown in the image diagram of FIG. 4, the error of the measurement values due to the radiation effects of multiple thermocouples is corrected using multiple measurement values. Yes, specifically, as shown in the image diagram of FIG. 5, the temperature gradient B is obtained from the apparent measured value, and from the obtained temperature gradient B, the radiation of the temperature sensitive part is calculated from the difference in temperature measured by each thermocouple. It is characterized in that the influence is estimated and the correct temperature (corrected temperature) Ta is obtained asymptotically by removing the influence in the calculation.

As a method for obtaining the correction temperature Ta, here, a method in which the heat balance of the temperature sensing portion and the equation of heat transfer (the theory of heat transfer) is combined is used. The heat balance in the thermocouple temperature sensing part in the atmosphere is expressed by the following formula (1) when heating by the internal current and heat exchange by boiling and condensation are ignored.
RN _u (λ / d) (Ts−Ta) = 0 (1)

Here, Ta is corrected temperature (true temperature), Ts is the apparent temperature (measured value), the radiation amount R is the thermocouple temperature sensing unit receives, _{N u} is the Nusselt number, _{d (d} 1, _{d 2} ...) Is the diameter of the thermocouple temperature sensitive part, and λ is the thermal conductivity.

When this equation (1) is transformed, the following equation (2) is obtained.
Ts−Ta = RN _u ⁻¹ dλ ⁻¹ (2)

With respect to the dimensionless number N _u (Nussert number) included in the expression (2), the relationship with other dimensionless numbers (reduction formula in heat transfer) can be expressed by expressions (3) and (4) in forced convection. .
^{_{N u = CR e n P r}} m ··· (3)
R _e = (ud / ν), P _r = (ν / a), ν = (μ / ρ), a = (λ / ρc _p ) (4)

Here, R _e : Reynolds number, P _r : Prandtl number, u: Flow velocity (= wind velocity), d: Diameter of thermocouple temperature sensing part (representative length), ν: Kinematic viscosity coefficient, a: Temperature conductivity, μ : Viscosity coefficient, ρ: density, c _p : specific heat.

  In this simplification formula, C, n, and m are constants obtained experimentally, and here, three experimental values are set as unknowns. In this case, among the other parameters, R and u change depending on the environmental conditions at the time of measurement, and the diameter d of the temperature sensing portion is a value that can be obtained in advance when the temperature sensor is manufactured.

When the above formulas (1), (3), and (4) are solved for the difference of Ts−Ta and the constant is A, the following relationship is obtained.
Ts−Ta = RN _u ⁻¹ dλ ^{−1
= Rc -1 u -n d (1} -n) ρ -n μ (n-m) c p -m λ (m-1) ··· (5)
= A × (R / u ⁿ ) × d ^(1-n) (6)

  From this equation (6), it can be understood that the measured value of the temperature generally has a larger error (radiation received by the temperature sensing unit) and a larger error as u (wind speed) is smaller. On the other hand, the error can be reduced as d (diameter of the temperature sensitive part) is smaller, but in theory, the error cannot be made zero. The temperature measuring device 10 of the present embodiment does not increase the ventilation speed as in the conventional thermometers, or reduce the temperature-sensitive part as much as possible to reduce the influence of radiation, but instead the volume of the temperature-sensitive part. By using a plurality of measured values simultaneously measured using a plurality of thermocouples having different values, the influence of radiation can be removed by calculation and the correct temperature can be obtained.

A specific solution method (how to obtain a correction temperature) is B = A × (R / u ⁿ ) in the above equation (6), and the relationship between the temperature, temperature sensor temperature, temperature sensor diameter. Becomes the following equation (7).
Ts−Ta = B × d ^(1-n) (7)

  Here, since there are three unknowns B, Ta, and n when measuring Ts, the true temperature Ta can be obtained by sequential calculation from Ts values for three different points d. That is, the temperature average value and the temperature gradient are calculated from the measured values of three points having different diameters (volumes) of the temperature sensing portion, and the true temperature (corrected temperature) Ta is calculated based on the relationship between the mean power values of the diameters based on a plurality of diameters. Can be sought. Of these, n is known to have a value of n = 1/2 (= 0.5) for various shapes (cylinder, flat plate, sphere, etc.). The true temperature (corrected temperature) can be obtained from the measurement by linear regression. However, since errors are actually included in individual measured values, a method of obtaining by linear regression from three points can be used for safety. In addition, since the accuracy of approximation is expected to increase as the number of measurement points increases, the number of measurement points can be increased to 4 points and 5 points.

  What is important is that the trend (for example, temperature gradient) is judged from a plurality of (multi-point) measurement values instead of one measurement value, and the true temperature is estimated. Moreover, when estimating the above-mentioned true temperature, it is not based on the theory of heat transfer, but the true temperature can also be obtained using an empirical approximate expression. And the calculation to find the true temperature from a plurality of measured values does not require so advanced calculation, so it can be automatically calculated by the program in the data logger 9 and designed by incorporating it into the substrate of the data logger 9. Is also possible.

Next, a specific procedure for calculating the temperature will be described below with reference to the control flow chart of FIG. As described above, the value of the parameter n is set to 0.5 (S1), and the diameters of the spheres of the thermosensitive portions of the thermocouples 2, 3, and 4 used in the temperature sensor 1 are d ₁ = 0.25, respectively. , D ₂ = 1, d ₃ = 4, and 1-n power (d ′) of the diameter d of the sphere is calculated, and d ₁ ′ = d ₁ ^1-n , d ₂ ′ = d ₂ ^1-n , d ₃ ′ = d ₃ ^1-n is obtained (S2). Then, the mean value of diameters (D) is obtained from the following equation (8) (S3). Further, the temperature average value (Ts) is calculated from the following equation (9) from the temperature measurement values Ts ₁ , Ts ₂ , Ts _{3 of the three} thermocouples 2, 3, 4 of the temperature sensor 1 (S 3).
D = (d ₁ '+ d ₂ ' + d ₃ ') / 3 (8)
Ts = (Ts ₁ + Ts ₂ + Ts ₃ ) / 3 (9)

Next, the gradient (temperature gradient) B shown in FIG. 5 is calculated from the following equation (10) (S4). Further, from the calculated temperature gradient B, an intercept Ta is calculated from the following equation (11) (S5), and a corrected temperature Ta with reduced radiation influence is calculated (S6). The corrected temperature Ta calculated in this way is a value close to the true temperature data at the measurement point.
B = {(d ₁ ′ −D) (Ts ₁ −Ts) + (d ₂ ′ −D) (Ts ₂ −Ts) + (d ₃ ′ −D) (Ts ₃ −Ts)} / {(d ₁ '-D) ² + (d ₂ ' -D) ² + (d ₃ '-D) ² } (10)

Then, the intercept Ta is calculated from the following equation (11) to determine the true temperature (corrected temperature) Ta. These calculations are executed by the temperature calculation means 11 and the correction temperature calculation means 12. Further, the calculated correction temperature Ta is displayed by the temperature display means 13, and the temperature can be measured quickly.
Ta = Ts−B × D (11)

Specifically, when the diameters of the spheres 2a, 3a, and 4a constituting the temperature sensitive parts of the thermocouples 2, 3, and 4 of the temperature sensor 1 are 0.25 mm, 1 mm, and 4 mm, respectively, The diameter ratio is 1: 4: 16, the volume ratio is 1: 64: 4096, and the value of the parameter n is “0.5”. The value of the sphere diameter d to the n-1th power (d ′) is ,Each,
(D ′ ₁ ) = 0.25 ^0.5 = 0.5, (d ′ ₂ ) = 1 ^0.5 = 1, (d ′ ₃ ) = 4 ^0.5 = 2, and these diameter power average values (D) is 1.167 from Equation (8).

And if the temperature measurement values Ts ₁ , Ts ₂ , Ts ₃ of the plurality of thermocouples 2, 3, 4 of the temperature sensor 1 are, for example, 25 ° C., 26 ° C., and 28 ° C., the temperature average value (Ts) is It becomes 26.333 degreeC by Formula (9). The 1-n power average value (D) of the sphere diameter d thus obtained is 1.167, and the temperature average of the measurement data of the three thermocouples 2, 3, 4 of the temperature sensor 1. The value (Ts) is 26.333, and the slope (temperature gradient) B shown in FIG. 5 is obtained from the average value of these by the formula (10), and B = 1.999≈2. Then, when the intercept Ta in FIG. 5 is obtained from the equation (11) and the calculated value Ta of the air temperature is obtained, Ta = 23.999≈24 ° C. The calculated value (corrected temperature) Ta obtained in this manner indicates a temperature close to the true temperature in which the influence of heat radiation applied to the spheres 2a, 3a, 4a constituting the temperature sensing portion is suppressed.

  The three thermocouples 2, 3 and 4 of the temperature sensor 1 constituting the temperature measuring device 10 are arranged such that the spheres 2a, 3a and 4a which are temperature sensing parts are arranged at equal intervals on the circumference. When the distance is equal, and the outdoor wind is installed outdoors, there is little interference with each other, and the influence of radiation can be kept small. In addition, the temperature measuring device 10 can obtain a calculated value (corrected temperature) close to the true air temperature while suppressing the influence of radiation from the measurement data of the plurality of thermocouples 2, 3, 4 of the temperature sensor 1.

  In the temperature measuring device 10 according to the present invention, the temperature is calculated by using the difference generated in the measured values of the plurality of thermocouples 2, 3, and 4, so that forced ventilation is not necessary, and temperature measurement is performed while saving power. Accuracy can be improved. In addition, since radiation shielding (shelter) is not required, the structure and arrangement of the temperature sensing unit are increased, and the entire measuring apparatus can be miniaturized so as not to disturb the measurement field. Furthermore, by making the temperature sensing part spherical, heat exchange on the surface is less affected by the wind direction, and a stable measurement value can be obtained. Moreover, the raw material and member used for the temperature measuring apparatus 10 can be comprised with an inexpensive thing, and a cost reduction can be achieved through size reduction of an apparatus and power saving.

  A temperature measuring device 10 according to the present invention is obtained by inserting a plurality of thermocouples 2, 3, 4 of a temperature sensor 1 into support tubes 2 b, 3 b, 4 b and integrating them with a grip part 5. By supporting the support tube in a rotatable manner by the grip portion 5, it is possible to fold the thermocouple extending in multiple directions in a compact manner, and to facilitate the transportation and storage operations. In addition, the connection to the data logger 9 is facilitated by the connection wire 6 in which the ends of the compensating conductors 2c, 3c, 4c of the thermocouples 2, 3, 4 are collected and connected together.

  Further, based on the above-mentioned theory of heat transfer using a plurality of thermocouples 2, 3, 4 having different volumes of the spheres 2 a, 3 a, 4 a of the temperature sensing part and using a plurality of data measured simultaneously. An example in which two correction temperatures are calculated will be described below with reference to FIGS. In this calculation example, five thermocouples having a sphere diameter of 0.28 mm, 0.5 mm, 1 mm, 2 mm, and 4 mm are used. Then, every hour from 4 o'clock in the morning of one day, nine temperature data are simultaneously measured at 5 o'clock, 6 o'clock, 7 o'clock, 8 o'clock, 9 o'clock, 10 o'clock, 11 o'clock and 12 o'clock. .

  A plurality of temperature data simultaneously measured in this manner is plotted in FIG. 7 where the horizontal axis is the sphere diameter d (mm) to the 0.5th power and the vertical axis is the temperature difference (° C.) from the standard thermometer. When a straight line close to the temperature data at each time is drawn, it can be seen that as the diameter of the sphere increases, the influence of radiation increases and the temperature difference increases. In addition, the straight lines L1 and L2 indicating the temperature data at 4 o'clock and 5 o'clock are less affected by radiation and the slope of the straight line (temperature gradient) is small, and the straight lines L3 and L4 connecting the temperature data at 9 o'clock and 11 o'clock are radiation The influence is large and the slope of the straight line (temperature gradient) is large. However, in the vicinity of “0” on the horizontal axis, the temperature difference between the straight line of each time and the standard clock is close to “0”, and it can be seen that temperature data (corrected temperature) close to the true temperature can be calculated by correction. .

FIG. 8 shows a straight line L5 approaching each temperature data when the horizontal axis is the measured value (° C.) of the standard thermometer and the vertical axis is the temperature data (° C.) of the multipoint temperature measuring device 10 of this embodiment. Is close to a straight line in the 45-degree direction, and the measured value of the multipoint thermometer approximates the measured value of the standard thermometer, indicating that a value close to true temperature data can be calculated. That is, if the straight line L5 is y = x, it means that the temperature measurement device 10 of the present embodiment and the measurement value of the standard thermometer match, but the straight line L5 is calculated by y = 1.0096x. -0.2134, which is almost the same. The correlation coefficient is as extremely high as R ² = 0.9985, and the root mean square error RMSE = 0.13 ° C. It can be seen that the temperature measuring apparatus 10 of the embodiment has a very small error.

  As described above, in the temperature measurement device 10 of the present embodiment, heat transfer studies are performed using a plurality of temperature data simultaneously measured by the temperature sensor 1 including a plurality of thermocouples 2, 3 and 4 having different volumes of the temperature sensing unit. By correcting each temperature calculated by the equation (6) based on the above theory and calculating the corrected temperature, one corrected temperature data close to the true temperature can be calculated.

  Another embodiment of the present invention will be described in detail with reference to FIGS. FIG. 9 is a perspective view of a main part showing another embodiment of the temperature sensor according to the present invention, and FIG. 10 is a schematic view of the temperature sensor of FIG. This embodiment is characterized in that the arrangement of a plurality of thermocouples constituting the temperature sensor is different from the above-described embodiment. Other substantially equivalent configurations are denoted by the same reference numerals, and detailed description thereof is omitted.

  9 and 10, a plurality of thermocouples 22, 23, and 24 constituting the temperature measuring unit of the temperature sensor 21 are inserted into three support tubes formed of stainless steel as in the above embodiment. For example, the thermocouple 22 is set so that the length of the horizontal portion of the support tube 22b is bent to 8 cm, the support tube 23b is formed linearly in the thermocouple 23, and the thermocouple 24 is formed of the support tube 24b. The length of the horizontal part is set to 6 cm. Then, the spheres 22a, 23a, 24a constituting the temperature sensitive parts of the thermocouples 22, 23, 24 are arranged to form right-angled triangles of 10 cm, 8 cm, 6 cm, respectively, and the volumes of the three spheres 22a, 23a, 24a are arranged. Are different, the diameter of each sphere is set.

  The temperature sensor 21 of this embodiment is configured to include a plurality of thermocouples 22, 23, 24 having different volumes of the temperature sensing portion, and the plurality of thermocouples 22, 23, 24 are bundled by the grip portions 25, 25. It is an integrated unit. Moreover, the temperature sensor 21 can be folded compactly by turning the thermocouple 24 around the grip portions 25 and 25, for example, and transportation and construction are facilitated.

  Also in this embodiment, different temperature data can be obtained by the three thermocouples 22, 23, 24 having different sphere diameters of the temperature sensor 21, and a temperature close to the true temperature can be obtained from these data. However, in this embodiment, the thermocouple 22 having a large diameter of the sphere 22a is arranged away from the thermocouple 24 having a medium diameter of the sphere 24a and the thermocouple 23 having a small diameter of the sphere 23a. The small thermocouple 23 is close to the thermocouple 24 having a small diameter of the sphere 24a. However, since the turbulence is different depending on the size of the sphere, the influence of the wind direction is any of W1, W2, and W3. It is difficult to receive. That is, when the sphere is large, the turbulence of the wind is large but it is separated, so that it is difficult to be affected. By arranging the thermocouples 22, 23, 24 of the temperature sensor 1 in this way, it is possible to measure the temperature with higher accuracy.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, in the above-described embodiment, an example of copper-constantan is shown as an example of a thermocouple for measuring the temperature, but it is needless to say that other thermocouples such as alumel-chromel can be used.

  Although the example of the stainless steel sphere was shown as a sphere which comprises a temperature sensing part, the sphere of another metal may be sufficient and what was formed with other materials, such as resin, may be sufficient. Moreover, although the several thermocouple which comprises the temperature sensor of this invention presupposes that the volume of the temperature sensing part differs, a temperature sensing part is as shown to Fig.11 (a). The shape is not limited to a sphere, and may be a rectangular parallelepiped such as a cylindrical body or a flat body as shown in FIGS. The temperature measuring device may be a device that does not have temperature display means and only outputs temperature data.

  In the above-described embodiment, as shown in FIG. 11 (a), the thermocouple temperature sensing part is a sphere, and the diameter da of the sphere is set variously so that the volume of the temperature sensing part is different. The correction temperature is calculated based on da, but when the thermocouple temperature sensing part is a cylinder as shown in FIG. 11B, the diameter db of the cylinder is a numerical value corresponding to the diameter of the sphere. Can be used as a numerical value for calculating the correction temperature. In addition, the diameter db can be changed and the height can be changed to obtain a similar cylindrical body.

  Further, when the thermocouple temperature sensing part is a flat plate as shown in FIG. 11C, the length dc of the diagonal line of the flat plate can be used as a numerical value for calculating the correction temperature. When one temperature sensing part is a flat plate, the flat body of the other temperature sensing part may be configured such that the ratio of the vertical, horizontal, and height is similar to that of one flat plate. .

  As an application example of the present invention, it is possible to measure the temperature of various gases in addition to the air temperature using the above-described temperature measuring device, and it can also be applied to the measurement of the temperature of mixed gas. In addition to use on agricultural land, etc., it can be applied to the use of many public institutions, producers, people related to agricultural facilities, temperature management of parks, schoolyards, etc. It becomes possible.

  1, 2: 1: Temperature sensor, 2, 3, 4, 22, 23, 24: Thermocouple, 2a, 3a, 4a, 22a, 23a, 24a: Thermocouple temperature sensing part (sphere), 2b, 3b, 4b, 22b, 23b, 24b: thermocouple support tube, 2c, 3c, 4c: thermocouple compensation conductor, 5, 25: grip portion, 6, 26: connection wire, 9: data logger, 10: temperature measuring device, 11 : Temperature calculation means, 12: Correction temperature calculation means, 12A: Calculation part, 12B: Correction temperature calculation part, 13: Temperature display means, 14: Temperature sensing part diameter input part

Further, in the temperature measuring device, the correction temperature calculations unit, the corrected temperature of Ta, the temperature mean value of the temperature calculated by the temperature calculation section Ts, the each sphere the temperature sensing unit The correction temperature Ta is calculated from the equation Ts−Ta = B × D, where D is the average power of diameters based on the diameter and B is the temperature gradient.
According to this configuration, based on the difference in the amount of radiation received by the plurality of thermocouple temperature sensing units, based on the average value of each temperature measured by the thermocouple temperature sensing unit and the diameter of each sphere of the thermocouple temperature sensing unit. The temperature gradient can be calculated from the power average value of the diameters, and a corrected temperature close to the true temperature can be calculated based on the theory of heat transfer.

The present invention relates like a to that temperature measuring device and a temperature measuring method measuring temperature, in particular, relates to a temperature measuring device and a temperature measuring method having improved measurement accuracy using a temperature sensor comprising a plurality of thermocouples.

The present invention has been made in view of such problems, and the object of the present invention is to simplify the configuration, reduce the device cost, improve the measurement accuracy, and improve the general temperature. can be used for various applications as a measuring apparatus, and to provide a difficulty has temperature measuring device and a temperature measuring method affected environment.
Another object is to provide solar radiation affected easily paddy field and wind, etc., the temperature temperature measuring device and a temperature measuring method suitable for the measurement of the outdoor, such as upland field.

To achieve the above object, a temperature measuring device according to the present invention, the volume is made of a plurality of thermocouples having different temperature sensing unit, calculating each temperature converts each electromotive force of the thermocouple of the plurality of And a correction temperature calculation means for calculating one correction temperature based on each temperature calculated by the temperature calculation means . The temperature sensing unit is a sphere. Further, the plurality of thermocouples are formed integrally with each of the temperature sensing portions being arranged at a predetermined interval and by collecting the end portions of the thermocouple on the side opposite to the temperature sensing portion. The plurality of thermocouples are preferably arranged at equal intervals on one virtual circumference.

The temperature measuring device of the present invention configured as described above has a phenomenon that when the volume of the thermosensitive portion of the thermocouple is different, there is a phenomenon in which the generated electromotive force (temperature) varies depending on the environment and the plurality of different temperatures. It is based on the new knowledge that a correction temperature close to one true temperature can be calculated by correcting the temperature, and a plurality of thermocouples with different volumes of the temperature sensitive part are made one temperature sensor. Thus, a plurality of temperature data with different generated electromotive forces can be obtained more accurately and easily, and a correction temperature close to the true temperature can be easily derived from the plurality of temperature data by subsequent data processing. It is what.
In addition, the temperature sensor of the present invention can reduce the number of parts and facilitate assembly of the apparatus and installation outdoors.

As a preferred specific embodiment of the temperature measuring device according to the present invention, the number of the plurality of thermocouples is preferably 3 to 5. Furthermore, it is preferable that the plurality of thermocouples are covered with a support pipe made of a stainless steel pipe , leaving the temperature sensitive portion. The support tube may be formed by bending the vertical portion, the horizontal portion, and the vertical portion continuously, or one of a plurality of thermocouples is formed in a straight line, and the remaining thermocouples are vertical portions. It is preferable that the horizontal portion and the vertical portion are bent continuously. According to this configuration, three to five thermocouples equally spaced on a single virtual circle on, it is possible to suppress the influence of natural wind, the temperature sensing a plurality of thermocouples in support tube If the coating is made while leaving the portion, durability against wind and rain can be improved.

According to the temperature measurement equipment according to the present invention, it is possible to calculate a plurality of temperature at the temperature calculation means using a plurality of thermocouples of the temperature sensor, based on the respective calculated by correcting temperature calculation section Temperature In order to calculate one correction temperature, it is possible to calculate a correction temperature close to the true temperature while suppressing the influence of radiation applied to each thermocouple.

As another aspect of the temperature measuring device according to the present invention, in the temperature measuring device in which the temperature sensing unit is a sphere, the correction temperature calculation means is a mean power average value based on the diameter of each sphere of the temperature sensing unit. A temperature calculating unit that calculates a temperature average value of each temperature of the temperature sensing unit, a diameter of each sphere, a power average value of the diameters, a temperature gradient based on each temperature, and the temperature average value. The correction temperature calculation means includes a correction temperature calculation unit that calculates the correction temperature based on the temperature average value, the diameter power average value, and the temperature gradient.
According to this configuration, the correction temperature calculation means calculates the correction temperature based on the temperature gradient of each temperature calculated based on a plurality of thermocouples having different diameters of the spheres of the temperature sensor of the temperature sensor. It is possible to calculate a correction temperature close to the true temperature while suppressing the influence of radiation.

The temperature measurement method according to the present invention is a temperature measurement method using a temperature sensor composed of a plurality of thermocouples having temperature-sensitive parts having different volumes, and measures each electromotive force of the plurality of thermocouples to measure the electromotive force. Each electromotive force is converted into each temperature, and one correction temperature is calculated based on each converted temperature.
Another aspect of the temperature measuring method of the present invention, the temperature sensing unit is a sphere, by measuring the electromotive force of the thermocouple of the plurality of converting the respective electromotive force at each temperature, the feeling The diameter power average value based on the diameter of each sphere of the warm part, the temperature average value of each temperature of the temperature sensing part, and the diameter of each sphere, the diameter power average value, the temperature, and the temperature average value The correction temperature is calculated based on a temperature gradient based on the above. Further, when the corrected temperature is Ta, the temperature average value of each temperature is Ts, the diameter power average value based on the diameter of each sphere of the temperature sensing portion is D, and the temperature gradient is B, the equation Ts−Ta The correction temperature Ta is calculated from B × D.
According to this configuration, each electromotive force of a plurality of thermocouples is converted into each temperature, and the correction temperature is calculated based on each converted temperature. Therefore, the true temperature is obtained based on the temperature gradient of each temperature. Close temperature can be measured.

Claims (14)

A temperature sensor having a plurality of thermocouples having a temperature sensing part,
The temperature sensor, wherein each of the thermosensitive parts of the thermocouple has a different volume.   The temperature sensor according to claim 1, wherein the temperature sensing unit is a sphere.   In the plurality of thermocouples, each of the temperature sensing portions is arranged at a predetermined interval, and ends of the thermocouples on the side opposite to the temperature sensing portion are gathered and formed integrally. The temperature sensor according to claim 1 or 2, wherein   The temperature sensor according to any one of claims 1 to 3, wherein the plurality of thermocouples are arranged at equal intervals on one virtual circumference.   The temperature sensor according to any one of claims 1 to 4, wherein the plurality of thermocouples is three to five.   The temperature sensor according to any one of claims 1 to 5, wherein the plurality of thermocouples are covered with a stainless steel pipe leaving the temperature sensing portion. A temperature measuring device comprising the temperature sensor according to any one of claims 1 to 6,
A temperature calculation means for calculating each temperature by converting each electromotive force of the plurality of thermocouples; a correction temperature calculation means for calculating one correction temperature based on each temperature calculated by the temperature calculation means; A temperature measuring device comprising: A temperature measuring device comprising the temperature sensor according to claim 2,
A temperature calculation means for calculating each temperature by converting each electromotive force of the plurality of thermocouples; a correction temperature calculation means for calculating one correction temperature based on each temperature calculated by the temperature calculation means; With
The correction temperature calculation means includes a diameter power average value based on a diameter of each sphere of the temperature sensing part, a temperature average value of each temperature of the temperature sensing part, and a diameter and a power average value of each sphere. And a temperature measuring device comprising a calculating unit for calculating a temperature gradient based on each temperature and the temperature average value.   The said correction temperature calculation means is provided with the correction temperature calculation part which calculates the said correction temperature based on the said temperature average value, the said diameter power average value, and the said temperature gradient. Temperature measuring device.   The correction temperature calculation unit sets the correction temperature to Ta, sets the temperature average value of each temperature calculated by the temperature calculation means to Ts, and calculates a diameter power average value based on the diameter of each sphere of the temperature sensing unit to D The temperature measuring device according to claim 9, wherein the correction temperature Ta is calculated from the equation Ts−Ta = B × D, where B is the temperature gradient.   The temperature measuring device according to any one of claims 7 to 10, wherein the temperature measuring device includes display means for displaying the correction temperature. A temperature measurement method using the temperature sensor according to any one of claims 1 to 6,
A temperature measuring method, wherein each electromotive force of the plurality of thermocouples is measured, each electromotive force is converted into each temperature, and one correction temperature is calculated based on each converted temperature. A temperature measurement method comprising the temperature sensor according to claim 2,
Measuring each electromotive force of the plurality of thermocouples and converting each electromotive force into each temperature;
The diameter power average value based on the diameter of each sphere of the temperature sensing part, the temperature average value of each temperature of the temperature sensing part, and the diameter of each sphere, the diameter power average value, the temperature and the temperature A temperature measurement method, wherein the correction temperature is calculated based on a temperature gradient based on an average value. Assuming that the correction temperature is Ta, the temperature average value of each temperature is Ts, the diameter power average value based on the diameter of each sphere of the temperature sensing part is D, and the temperature gradient is B, the equation Ts−Ta = B The temperature measuring method according to claim 13, wherein the correction temperature Ta is calculated from × D.

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