JPWO2021019712A1 - How to change the configuration of the temperature measurement system, temperature measurement sensor unit and temperature measurement system - Google Patents

Abstract

The temperature measuring system 10 has two terminals 22 and 24, and energizes between them to measure electrical resistance. One ends of electric wires 30 and 32 are connected to the two terminals 22 and 24, respectively. A resistance temperature detector 44 and a bypass electric wire 42 are connected in parallel to the other ends of the electric wires 30 and 32, and the resistance temperature detector 44 and the bypass electric wire 42 are selectively switched by a switch 46. The electrical resistance or corresponding temperature of the resistance temperature detector is calculated based on the electrical resistance measured when the bypass wire is energized and off.

Description

The present invention relates to a temperature measuring system, a temperature measuring sensor unit, and a method for changing the configuration of the temperature measuring system.

A technique for measuring temperature using a resistance temperature detector is known. The temperature measurement may be performed by a 3-wire system or a 2-wire system.

FIG. 6 is a diagram showing an outline of a conventional three-wire temperature measuring system 110 (see, for example, Patent Documents 1 to 3 below). Here, three electric wires 114, 116, and 118 are connected to the controller 112. The electric wires 114, 116, and 118 have the same length, thickness, and material, and all have the same electric resistance R. However, the electric resistance R changes depending on the temperature.

The resistance temperature detector 120 has an electric resistance Rpt1 that changes depending on the temperature, and its two ends are connected to the tips of the electric wires 114 and 116. As the resistance temperature detector 120, for example, Pt100, which is a standard product made of platinum and whose electrical resistance at 0 ° C. is set to 100Ω, is used. In the resistance temperature detector 120, which is a standard product, the relationship between the electrical resistance and the temperature is clear, and the temperature can be obtained from the electrical resistance of the resistance temperature detector 120.

The tip of the electric wire 118 is also connected to the tip of the electric wire 116. The controller 112 controls a built-in switch to disconnect the electric wire 118 from the circuit and pass a current through the circuit (indicated by the arrow 122) passing through the electric wires 114 and 116, whereby the voltage of this circuit and the electric resistance R1 To measure:
R1 = R + Rpt1 + R ... (Equation 1)
The electrical resistance R1 is obtained by dividing the measured voltage by the current.

Next, the controller switches the switch to disconnect the electric wire 114 from the circuit and pass a current through the circuit (indicated by the arrow 124) passing through the electric wires 116 and 118 to measure the voltage of this circuit and the electric resistance R2. do:
R2 = R + R ... (Equation 2)
From Equations 1 and 2, the electrical resistance Rpt1 of the resistance temperature detector 120 can be obtained.
Rpt1 = R1-R2 ... (Equation 3)
That is, the electric resistance Rpt1 corresponds to the difference between the electric resistances R1 and R2 obtained by measurement. By obtaining the electric resistance Rpt1, the temperature of the resistance temperature detector 120 can be obtained.

FIG. 7 is a diagram showing an outline of a conventional two-wire temperature measuring system 130. Two electric wires 134 and 136 having the same electric resistance R are connected to the controller 132. A resistance temperature detector 138 having an electric resistance Rpt2 is connected to the tip of the electric wires 134 and 136. As the resistance temperature detector 138, one having an electric resistance Rpt2 sufficiently larger than the electric resistance R of the electric wire and having the following relationship is used.
Rpt2 >> R ・ ・ ・ (Equation 4)
Specific examples thereof include Pt1000 and Pt3000, which are made of platinum and have an electric resistance of 1000Ω or 3000Ω at 0 ° C., which is a standard product.

In the controller 132, the electric resistance R3 of this circuit is measured by passing a current through a circuit (indicated by an arrow 140) passing through the electric wires 134 and 136 and measuring the voltage.
R3 = R + Rpt2 + R ... (Equation 5)
Here, using Equation 4, the following approximation can be performed.
R3 = Rpt2 (1 + 2 * R / Rpt2)
≒ Rpt2 ・ ・ ・ (Equation 6)
Therefore, the electric resistance Rpt2 has the same value as the measured electric resistance R3. By obtaining the electric resistance Rpt2, the temperature of the resistance temperature detector 138 can be obtained.

Jitsukaisho 61-17634 Jikkai Sho 62-53328 Japanese Unexamined Patent Publication No. 4-52529

The two-wire temperature measuring system 130 shown in FIG. 7 is often used in buildings with a long age. When replacing the temperature measurement system, the resistance temperature detector 138 will be replaced. However, if the resistance temperature detector 138 is replaced from Pt1000 or Pt3000, which has been widely used in the past, to Pt100, which is currently used as a standard, the equation 4 is not satisfied, and the temperature measurement error in the temperature measurement system 130 becomes large. It will increase. Therefore, it cannot be simply exchanged for Pt100. For this reason, in the replacement work, for example, it is necessary to introduce an expensive sensor having a built-in 4 to 20 mA output converter, or to rewire the electric wire and shift to the 3-wire system.

An object of the present invention is to make it possible to use a resistance temperature detector having a small electrical resistance in a two-wire temperature measuring system.

The temperature measuring system according to the present invention has two terminals, and one end is connected to each of the two terminals and a measuring means for measuring the electrical resistance between the two terminals by energizing between the two terminals. Two electric wires, a resistance temperature detector and a bypass electric wire connected in parallel to the other ends of the two electric wires, a switch for switching the energization of the bypass electric wire on and off, and energization of the bypass electric wire. Calculation to calculate the electrical resistance of the resistance temperature detector or the corresponding temperature based on the electrical resistance measured by the measuring means when is on and the electrical resistance measured by the measuring means when is off. It is characterized by providing means.

One aspect of the temperature measuring system according to the present invention is characterized in that the switch autonomously switches on and off.

In one aspect of the temperature measuring system according to the present invention, the calculation means is off from the electric resistance when the bypass wire is energized based on the fluctuation of the electric resistance measured by the measuring means. The electric resistance in the case of the above is detected, and the electric resistance of the resistance temperature detector or the corresponding temperature is calculated.

In one aspect of the resistance temperature measuring system according to the present invention, the electrical resistance or the corresponding temperature of the resistance temperature detector calculated by the calculation means is compared with the comparison data to detect deterioration or abnormality of the resistance temperature measuring system. It is characterized in that it is provided with a deterioration abnormality detecting means.

In one aspect of the resistance temperature measuring system according to the present invention, the comparison data is data on the electrical resistance or the corresponding temperature of the resistance temperature detector calculated in the past.

In one aspect of the resistance temperature measuring system according to the present invention, the comparison data is data on the electrical resistance or the corresponding temperature of another resistance temperature detector arranged in a common or similar space. do.

In one aspect of the resistance temperature measuring system according to the present invention, when the switch turns on the energization of the bypass electric wire, it switches the energization of the resistance temperature detector off and turns on the bypass electric wire. When the energization is switched off, the energization of the resistance temperature detector is switched on.

In one aspect of the temperature measuring system according to the present invention, the switch switches the energization of the bypass electric wire on and off in a state where the two electric wires and the resistance temperature measuring resistor are connected. It is characterized by.

The temperature measuring sensor unit according to the present invention is characterized by including a temperature measuring resistor and a bypass electric wire connected in parallel, and a switch for switching on / off of energization of the bypass electric wire.

In the method for changing the configuration of the temperature measuring system according to the present invention, the measuring means having two terminals, energizing between the two terminals to measure the electrical resistance between the two terminals, and each of the two terminals This is a method of modifying the configuration of a resistance temperature measuring system including two electric wires to which one end is connected and a resistance temperature detector connected to the other end of the two electric wires, and the resistance temperature detector is removed. It is characterized by including a step and a step of attaching the temperature measuring sensor unit to the other ends of the two electric wires.

According to the present invention, a two-wire type temperature measurement can be performed by using a resistance temperature detector having a smaller electrical resistance than the conventional one.

It is a schematic block diagram of the two-wire temperature measuring system which concerns on embodiment. It is a figure which shows the schematic configuration example of a switch. It is a figure which shows the example of the comparison data. It is a figure which shows another example of the contrast data. It is a schematic block diagram of the two-wire temperature measuring system which concerns on another embodiment. It is a schematic block diagram of the three-wire type temperature measuring system which concerns on the prior art. It is a schematic block diagram of the two-wire temperature measurement system which concerns on the prior art.

Hereinafter, embodiments will be described with reference to the drawings. In the description, specific embodiments are shown for ease of understanding, but these are examples of embodiments, and various other embodiments can be taken.

FIG. 1 is a diagram showing a schematic configuration of a temperature measuring system 10 according to an embodiment. The temperature measuring system 10 includes a controller 20, two electric wires 30 and 32, a temperature measuring sensor unit 40, and a PC (Personal Computer) 50.

In the embodiment, it is assumed that the temperature measuring system 10 is installed in the building. The controller 20 is a device installed in the central control room of the building to control the temperature measurement in the building. The controller 20 includes a plurality of sets of two terminals, including a set of the two terminals 22 and 24 shown in the figure. Further, the controller 20 measures a switching circuit for switching a set of two terminals to be measured, a constant current circuit for passing a constant current to the set of two terminals to be measured, and a voltage between the two terminals to which the current is passed. It is also equipped with a voltmeter to calculate the electrical resistance by dividing the measured voltage by the current and a processor to calculate the temperature from the electrical resistance. A voltmeter and a processor are examples of measuring means for measuring the electrical resistance between two terminals. The processor is also an example of a calculation means for calculating the electrical resistance of a resistance temperature detector or the corresponding temperature.

One ends of the electric wires 30 and 32 are connected to the terminals 22 and 24, respectively, and the other ends 30a and 32a are connected to the temperature measurement sensor unit 40. The electric wires 30 and 32 extend from the central control room to the installation location of the temperature measurement sensor unit 40, and typically have a length of several tens of meters or 100 meters or more. The electric wires 30 and 32 each have an electric resistance R.

The end of the temperature measurement sensor unit 40 is connected to the terminals 30a and 32a at the tips of the electric wires 30 and 32, respectively. The temperature measurement sensor unit 40 includes a bypass electric wire 42 having an electric resistance Rb, a resistance temperature detector 44 having an electric resistance Rpt3, and a switch 46. The bypass wire 42 and the resistance temperature detector 44 are connected in parallel. The switch 46 selectively connects the bypass wire 42 and the resistance temperature detector 44. That is, the switch 46 turns on the bypass wire 42 (that is, in a state where it can be energized) and turns off the resistance temperature detector 44 (that is, in a state where it is not energized), or turns off the bypass wire 42 and turns on the resistance temperature detector 44. Switch whether to do it. The switch 46 has an electrical resistance Rs.

The PC 50 is a computer in which computer hardware such as a processor, a memory, and a touch panel is controlled by an OS (Operation System), an application program (application), and the like. The PC 50 is an example of deterioration abnormality detecting means, and is connected to the controller 20 and detects deterioration or abnormality of the temperature measuring system 10 based on the temperature data output by the controller 20.

Here, the flow of temperature measurement in the temperature measuring system 10 will be described. In the temperature measuring system 10, the switch 46 is switched to perform measurement. The electrical resistance R4 when the bypass wire 42 is turned on and the resistance temperature detector 44 is turned off by the switch 46 is as follows:
R4 = R + Rs + Rb + R ... (Equation 7)
The electric resistance R4 on the left side is obtained by dividing the measured value of the voltmeter by the current.

The electrical resistance R5 when the bypass wire 42 is turned off and the resistance temperature detector 44 is turned on by switching the switch is as follows:
R5 = R + Rs + Rpt3 + R ... (Equation 8)
The electric resistance R5 on the left side is obtained by dividing the measured value of the voltmeter by the current.

From equations 7 and 8, the following equation is obtained for the electrical resistance Rpt3 of the resistance temperature detector 44:
Rpt3 = R5-R4 + Rb ・ ・ ・ (Equation 9)
The bypass electric wire 42 is a very short (for example, 0.1 m) conductor, and the magnitude of the electric resistance Rb is equal to or less than the error in the electric resistance Rpt3 of the resistance temperature detector 44, and thus can be ignored. Therefore, Equation 9 can be approximated as:
Rpt3 ≒ R5 − R4 ・ ・ ・ (Equation 10)

According to Equation 10, the electrical resistance Rpt3 of the resistance temperature detector 44 is equal to the difference between the two electrical resistances R5 and R4 obtained by switching the switch 46. The electric resistance Rpt3 does not have a binding condition corresponding to the equation 4 in the above-mentioned two-wire temperature measuring system 130. Therefore, as the resistance temperature detector 44, not only Pt1000 or Pt3000 can be used, but also Pt100, which is currently used as a standard, can be used.

In the controller 20, for example, in the form of a look-up table, information on the relationship between the electric resistance Rpt3 and the temperature is stored in the memory. Then, the processor calculates the temperature corresponding to the electric resistance Rpt3 by linear interpolation or the like. In the temperature measuring system 10, it is necessary to measure the temperature with the target accuracy. In normal building management, the target accuracy is set to about plus or minus 0.5 ° C. Even when the resistance temperature detector 44 of Pt100 is used as the resistance temperature detector 44, the effect of ignoring the electrical resistance Rb of the bypass wire 42 when deriving the equation 10 is very small, and there is no problem with this target accuracy. Can be achieved.

The controller 20 measures the temperature at many points in the building according to the program. Specifically, the controller 20 sequentially switches the circuit for the point to be measured by the internal switch, and performs the temperature measurement based on the above equation 10. The measurement result is stored in the storage device.

Here, an example of the switch 46 will be described with reference to FIG. FIG. 2 is a diagram showing an example of the switch 46a that connects and disconnects the terminal 30a and the bypass electric wire 42 among the switches 46.

The switch 46a is formed by using an NPN junction type bipolar transistor 64 which is a semiconductor element. A terminal 30a is connected to the collector of the bipolar transistor 64, and a bypass electric wire 42 is connected to the emitter. The base current is input to the base from the crystal oscillator circuit 62. The crystal oscillator circuit 62 is built in the temperature measuring sensor unit 40 and is driven by a direct current from the battery 60 to output a base current that becomes a timing signal. Examples of the timing signal include a signal that repeats a state in which the base current is set to 0 (voltage is 0V) for 1 second and a predetermined base current is passed for the next 1 second (a predetermined voltage is applied). The switch 46a cuts the terminal 30a and the bypass wire 42 when the base current is not passed, and connects the terminal 30a and the bypass wire 42 when a predetermined base current is passed.

Similarly, another bipolar transistor is provided between the terminal 30a and the resistance temperature detector 44, and control is performed by a signal obtained by inverting the timing signal. As a result, the switch 46 can be formed. By sharing the characteristics of the two bipolar transistors and giving them the same level of electrical resistance Rs, the influence of the electrical resistance Rs can be ignored (that is, the electrical resistance Rs of the switch 46 in Equations 7 and 8 becomes Since the values are the same, Equation 9 is obtained).

The switch 46 illustrated in FIG. 2 autonomously switches on and off in the temperature measurement sensor unit 40. Here, autonomous means that the temperature measuring sensor unit 40 operates independently without being controlled by the controller 20 or the PC 50. Therefore, the controller 20 needs to detect the changeover of the switch 46. As is clear from Equations 7 and 8, the electrical resistance R5 when the bypass wire 42 is turned off and the resistance temperature detector 44 is turned on is the case where the bypass wire 42 is turned on and the resistance temperature detector 44 is turned off. It is clearly larger than the electrical resistance R4. Therefore, the controller 20 detects the switching state of the switch 46 by detecting the fluctuation of the magnitude of the electric resistance (or the magnitude of the voltage measured by the voltmeter).

The switch 46 can be formed in various forms by using a semiconductor element other than those illustrated in FIG. Further, the switch 46 may be formed by using a relay instead of the semiconductor element or in combination with the semiconductor element. A relay has a drawback that the degree of deterioration is more severe than that of a semiconductor element, but it has an advantage that the electric resistance when it is turned on can be made very small.

As the switch 46, a switch 46 that operates under the control of the controller 20 can be used instead of the autonomous switch 46. Examples of such a switch 46 include a switch that operates based on an electric signal transmitted from the controller 20 via the electric wire 30.

Further, in the example of FIG. 2, the switch 46 is operated by the built-in battery 60. Although the battery 60 is consumed with time, the temperature measuring system 10 can be continuously operated by replacing the battery 60 at the timing of maintenance and management of the building. However, instead of the battery 60, for example, a capacitor may be provided, electric energy may be stored based on the electric power from the electric wire 30, and the switch 46 may be driven.

Subsequently, the operation of the PC 50 will be described. In the PC 50, by inputting the temperature measured by the controller 20 and comparing it with the comparison data to be compared, the temperature measuring system 10 detects deterioration or abnormality in which the correct temperature cannot be measured.

FIG. 3 is a diagram illustrating a case where past log data at the same point is used as comparison data. FIG. 3 illustrates log data of temperature measurement on the assumption that the resistance temperature detector 44 of the temperature measurement system 10 is provided at the second point of Room 4 on the 18th floor of Building A. The log data is provided with items of date, time, and temperature, and log data for the past several years is recorded in chronological order. According to the illustrated log data on August 1, 2018, the temperature was 27.5 ° C at 10:00, 27.8 ° C at 10:15, and 27.4 ° C at 10:30. The temperature was controlled by the air conditioner.

Here, it is assumed that the present time is August 1, 2019. On this day, the values of 27.9 ° C. at 10:00, 35.5 ° C. at 10:15, and 35.2 ° C. at 10:30 were measured. The PC50 compares the measured temperature with the temperature at the same point at the same time in the past from time to time. In the example of FIG. 3, it is compared with the data at the same time on August 1, 2018, which is one year ago. As a result, at 10:00, there is only a difference of + 0.4 ° C compared to the data at 10:00 a year ago, and the reference value (for example, plus or minus 3 degrees or plus or minus 5 degrees). It is judged that there is no particular deterioration or abnormality within the range of. However, at 10:15, the temperature is + 7.7 ° C., which is higher than the log data at 10:15 one year ago, and it is judged that the temperature exceeds the reference value. Further, at 10:30, the temperature is + 7.8 ° C. as compared with the log data at 10:30 one year ago, and it is also judged that the reference value is exceeded. If the condition for detecting deterioration or abnormality is that the reference value is exceeded twice in a row, the PC 50 determines that the deterioration or abnormality has occurred at 10:30. Therefore, the PC 50 notifies the maintenance manager by displaying a screen indicating that deterioration or abnormality has been detected at the second point of Room 4 on the 18th floor of Building A.

In the example shown in FIG. 3, the log data of the same month one year ago was compared, but other comparison data can be selected. For example, it may be compared with the same day of the week around one year ago, or it may be compared with the average value of a plurality of days around one year ago. Moreover, it is conceivable that such a comparison target is not limited to the past one year but also the past several years.

FIG. 4 is a diagram illustrating a mode in which measurement results by another resistance temperature detector arranged in a common or similar space are used as comparison data. FIG. 4 illustrates log data of temperature measurement by another resistance temperature detector provided at the first point of Room 4 on the 18th floor of Building A. That is, FIG. 4 shows the temperature measurement results at different points in the same room (an example of a space in which air conditioning and the like are common) in the same building as that shown in FIG. At the first point, on August 1, 2019, at the present time, 28.0 ° C was measured at 10:00 ° C, 27.9 ° C at 10:15, and 27.7 ° C at 10:30. doing.

In PC50, the temperature of the second point shown in FIG. 3 is compared with the temperature of the first point at any time. As a result, at 10:00, the second point is + 0.1 ° C. compared to the first point, and is within the range of the reference value (for example, plus or minus 1.5 degrees or plus or minus 2 degrees). Judge that there is. However, at 10:15, it is determined that the second point is + 7.6 ° C. compared to the first point and exceeds the reference value. Then, at 10:30, it is determined that the second point is + 7.5 ° C. as compared with the first point and also exceeds the reference value. If the condition for detecting deterioration or abnormality is that the reference value is exceeded twice in a row, the PC 50 determines that the deterioration or abnormality has occurred at 10:30.

However, it is not possible to determine which of the first point and the second point is normal by comparing only the two points between the first point and the second point in Room 4 on the 18th floor of Building A. Therefore, in reality, a comparison between 3 points or more is performed to identify a point that may be deteriorated or abnormal. When the PC50 detects deterioration or abnormality, it notifies the maintenance manager by displaying a screen indicating that deterioration or abnormality has been detected for the second point of Room 4 on the 18th floor of Building A.

In the detection of deterioration or abnormality, when the temperature exceeds the reference value only at a certain point, the deterioration or abnormality related to the point is detected. In the example of the temperature measuring system 10 of FIG. 1, it is determined that deterioration or abnormality has occurred in the electric wires 30, 32 or the temperature measuring sensor unit 40, or the contacts thereof. On the other hand, when the temperature exceeds the reference value at a plurality of points, it is determined that the device in the controller 20 common to these points has deteriorated or has an abnormality.

In the example shown in FIG. 4, it is compared with the measurement result of another resistance temperature detector at different points in the same room, but it is compared with the measurement result of another resistance temperature detector in a similar space having the same purpose. It is also possible. For example, when the resistance temperature detector 44 is installed in an office space, it may be compared with the measurement result in another office space on the same floor or a different floor.

The setting of reference values and the detection conditions for deterioration or abnormality can be changed in various ways. For example, it is conceivable to analyze the past log data that is assumed to be normal and set the reference value to a value that does not include the temperature variation in the normal case. Further, as a condition for detecting deterioration or abnormality, an example may be given in which the deterioration or abnormality is immediately determined when the deterioration or abnormality is exceeded once, not when the deterioration or abnormality is exceeded twice in succession.

Subsequently, a modified example of the embodiment will be described with reference to FIG. FIG. 5 is a diagram showing a schematic configuration of the temperature measuring system 70 according to the modified example. FIG. 5 is a diagram corresponding to FIG. 1, and the same or corresponding configurations as those of the temperature measuring system 10 shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted or simplified.

In the temperature measuring system 70, the temperature measuring sensor unit 80 is attached instead of the temperature measuring sensor unit 40 in the temperature measuring system 10. In the temperature measurement sensor unit 80, a resistance temperature detector 84 having an electric resistance Rpt4 and a bypass electric wire 82 having an electric resistance Rb are connected in parallel. Further, the temperature measuring sensor unit 80 is provided with a switch 86 having an electric resistance Rs and controlling the connection or disconnection of the bypass electric wire 82.

In the temperature measuring system 70, similarly to the temperature measuring system 10, the controller 20 measures the voltage and the electrical resistance of the circuit in the closed state and the open state of the switch 86. The electrical resistance R6 when the switch 86 is turned on (connected) is as follows:
R6 = R + (Rb + Rs) Rpt4 / (Rpt4 + Rb + Rs)
+ R ・ ・ ・ (Equation 11)
The electrical resistance R6 is obtained by dividing the measured value of the voltmeter by the current.

The electrical resistance R7 when the switch 86 is switched off (cutting the bypass wire 82) is as follows:
R7 = R + Rpt4 + R ... (Equation 12)
The electrical resistance R7 is obtained by dividing the measured value of the voltmeter by the current.

The following equations are obtained from Equations 11 and 12.
Rpt4 / (1+ (Rb + Rs) / Rpt4) = R7-R6
... (Equation 13)
Here, when it can be regarded as (Rb + Rs) / Rpt4 << 1, Equation 13 can be approximately transformed as follows.
Rpt4 ≒ R7-R6 ... (Equation 14)

Equation 14 has the same format as Equation 10 in the temperature measuring system 10. Generally, the electrical resistance Rb of the bypass wire 82 is small. Therefore, if the electrical resistance Rs of the switch 86 can be reduced, the temperature measuring sensor unit 80 in the temperature measuring system 70 can be used instead of the temperature measuring sensor unit 40 in the temperature measuring system 10. As the switch 86, for example, a switch similar to the switch 46a shown in FIG. 2 or a switch using a relay can be used. Further, as the resistance temperature detector 84, not only Pt1000 or Pt3000 can be used, but also Pt100, which is currently used as a standard, can be used.

The temperature measurement systems 10 and 70 shown above can be newly introduced into a newly built building or the like. Since the temperature measuring systems 10 and 70 are of the two-wire system, the number of electric wires can be reduced as compared with the three-wire temperature measuring system 110 described above with reference to FIG. Further, the temperature measuring systems 10 and 70 can be introduced by replacing the two-wire temperature measuring system 130 shown in FIG. 7. In this case, a configuration change method including a step of replacing the resistance temperature detector 138 of the temperature measuring system 130 with the temperature measuring sensor unit 40 or the temperature measuring sensor unit 80 and a step of replacing the controller 132 with the controller 20 is performed. Then, the temperature measuring systems 10 and 70 can be used. Further, by detecting deterioration or abnormality by the PC 50, maintenance management of the temperature measuring system 10 can be performed at an appropriate timing.

In the above description, in the temperature measuring systems 10 and 70, the controller 20 calculates the temperature based on the measurement of the voltage and the electric resistance, and the PC 50 deteriorates or abnormalizes the temperature measuring systems 10 and 70 based on the calculated temperature. Was supposed to be detected. However, for example, the function of the PC 50 may be provided to the controller 20. Further, the function of the PC 50 may be performed by a computer at a remote location.

Further, in the above description, in the temperature measuring systems 10 and 70, it is assumed that two electric wires 30 and 32 having substantially the same length, thickness, material and electric resistance are used. However, even if the electric resistances of the two electric wires 30 and 32 are different, the equations 10 and 14 can be derived, and it is not necessary to make the length, the thickness, and the material the same.

10 resistance temperature system, 20 controller, 22 terminals, 24 terminals, 30, 32 wires, 30a, 32a terminals, 40 resistance temperature sensor unit, 42 bypass wires, 44 resistance temperature detectors, 46, 46a switches, 60 batteries, 62 crystals Oscillation circuit, 64 bipolar transistor, 70 resistance temperature system, 80 resistance temperature sensor unit, 82 bypass wire, 84 resistance temperature detector, 86 switch, 110 resistance temperature system, 112 controller, 114, 116, 118 resistance wire, 120 resistance temperature detector Body, 122, 124 arrows, 130 resistance temperature systems, 132 controllers, 134, 136 wires, 138 resistance temperature detectors, 140 arrows.

Claims (10)

A measuring means that has two terminals, energizes between the two terminals, and measures the electrical resistance between the two terminals.
Two electric wires with one end connected to each of the two terminals,
A resistance temperature detector and a bypass wire connected in parallel to the other ends of the two wires,
A switch that switches the energization of the bypass wire on and off,
Based on the electrical resistance measured by the measuring means when the bypass wire is energized on and the electrical resistance measured by the measuring means when the bypass wire is off, the electrical resistance or the corresponding of the resistance temperature detector. A calculation method for calculating the temperature to be used, and
A temperature measurement system characterized by being equipped with. In the temperature measuring system according to claim 1,
The switch is a temperature measurement system characterized in that it autonomously switches on and off. In the temperature measuring system according to claim 2,
Based on the fluctuation of the electric resistance measured by the measuring means, the calculating means detects the electric resistance when the bypass wire is energized on and the electric resistance when the bypass wire is off, and measures the electric resistance. A resistance temperature measuring system that calculates the electrical resistance of a resistance thermometer or the corresponding temperature. In the temperature measuring system according to claim 1,
It is characterized by comprising a deterioration abnormality detecting means for detecting the deterioration or abnormality of the temperature measuring system by comparing the electrical resistance or the corresponding temperature of the temperature measuring resistor calculated by the calculating means with the comparison data. Temperature measurement system. In the temperature measuring system according to claim 4,
The temperature measuring system, characterized in that the comparison data is data on the electrical resistance or the corresponding temperature of the resistance temperature detector calculated in the past. In the temperature measuring system according to claim 4,
The temperature measurement system, characterized in that the comparison data is data about the electrical resistance or the corresponding temperature of another resistance temperature detector arranged in a common or similar space. In the temperature measuring system according to claim 1,
The switch switches the energization of the resistance temperature detector to off when the energization of the bypass wire is switched on, and turns off the energization of the bypass wire when the energization of the bypass wire is switched off. A temperature measurement system characterized by switching the energization of the resistor on. In the temperature measuring system according to claim 1,
The switch is a temperature measuring system characterized in that, in a state where the two electric wires and the temperature measuring resistor are connected, the energization of the bypass electric wire is switched on and off. With resistance temperature detectors and bypass wires connected in parallel,
A switch that switches the energization of the bypass wire on and off,
A temperature measurement sensor unit characterized by being equipped with. A measuring means that has two terminals, energizes between the two terminals, and measures the electrical resistance between the two terminals.
Two electric wires with one end connected to each of the two terminals,
A resistance temperature detector connected to the other end of the two wires,
It is a method of changing the configuration of the temperature measurement system equipped with
The step of removing the resistance temperature detector and
The step of attaching the temperature measurement sensor unit according to claim 9 to the other ends of the two electric wires,
A method of modifying the configuration of a temperature measuring system, which comprises.

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