Physical quantity measuring device, calibration program, and calibration method

Abstract

This physical quantity measuring device comprises a first sensor capable of measuring a first physical quantity value of an object being measured, a second sensor capable of measuring the first physical quantity value of the object being measured or a second physical quantity value correlated with the first physical quantity value, and a calibrating unit that calibrates the first sensor using the measurement value from the first sensor and the measurement value from the second sensor, wherein the first sensor is provided so as to be positioned on a first pathway through which the object being measured flows, and the second sensor is disposed in a measuring environment in which deterioration is less likely to occur than in the measuring environment of the first sensor.

Description

Substance Quantity Measuring Device, Calibration Program, and Calibration Method

[0001] The present invention relates to a substance quantity measuring device, a calibration program, and a calibration method.

[0002] Conventionally, a residual chlorine concentration meter in liquid that can measure the residual chlorine concentration of a liquid has been known (such as Patent Document 1). In the residual chlorine concentration meter in liquid described in Patent Document 1, the residual chlorine concentration in the sample water is measured using the voltage between both electrodes generated when the working electrode and the reference electrode are immersed in the sample water.

[0003] Japanese Patent Application Laid-Open No. 2006-090986

[0004] However, in the residual chlorine concentration meter in liquid described in Patent Document 1, measurement errors may occur due to reasons such as the liquid to be measured being different each time or the electrodes being consumed during measurement. Therefore, the user has a problem that every time they try to measure the residual chlorine concentration, they must manually calibrate according to the calibration method described in the product instruction manual or the like.

[0005] The present invention relates to a substance quantity measuring device, a calibration program, and a calibration method that can reduce the frequency of manual calibration.

[0006] The substance quantity measuring device according to the present invention includes a first sensor that can measure a first substance quantity value of a measurement object, a second sensor that can measure the first substance quantity value of the measurement object or a second substance quantity value correlated with the first substance quantity value, and a calibration unit that calibrates the first sensor using the measurement value of the first sensor and the measurement value of the second sensor. The first sensor is provided so as to be located on a first path through which the measurement object flows, and the second sensor is arranged in a measurement environment that is less likely to deteriorate than the first sensor.

[0007] In the substance quantity measuring device according to the present invention, the second sensor is provided so as to be located on a second path through which the measurement object flows. The second sensor is configured to be able to switch between a measurement state and a non-measurement state, and the measurement interval for the second sensor may be configured to be longer than the measurement interval for the first sensor.

[0008] In the material quantity measuring device according to the present invention, the second sensor is provided so as to be located on a second path through which the object to be measured flows, and the cross-sectional area of ​​the space in which the second sensor is located may be larger than the cross-sectional area of ​​the space in which the first sensor is located.

[0009] In the material quantity measuring device according to the present invention, the second sensor is positioned on a second path through which the object to be measured flows, and a switching unit may be provided between the first path and the second path that can switch between a flowing state in which the object to be measured flows in the second path and a non-flowing state in which the object to be measured does not flow in the second path.

[0010] The material quantity measuring device according to the present invention may include a first flow cell capable of housing the first sensor and a second flow cell capable of housing the second sensor.

[0011] In the material quantity measuring device according to the present invention, the first sensor and the second sensor each have a working electrode and a reference electrode, and the working electrode may be a silver / silver chloride electrode.

[0012] The calibration program according to the present invention is a calibration program that causes a material quantity measuring device, which includes a first sensor capable of measuring a first material quantity of an object to be measured, and a second sensor capable of measuring the first material quantity of the object to be measured or a second material quantity correlated with the first material quantity, to perform a calibration process to calibrate the first sensor, wherein the calibration program causes the material quantity measuring device to perform a first measurement process in which the first sensor, which is placed on a first path through which the object to be measured flows, measures the first material quantity of the object to be measured; a second measurement process in which the second sensor, which is placed in a measurement environment less prone to deterioration than the first sensor, measures the first material quantity of the object to be measured or the second material quantity of the object to be measured; and a calibration process in which the first sensor is calibrated using the measured values ​​of the first sensor and the second sensor.

[0013] A calibration method according to the present invention is a calibration method for calibrating a first sensor using a first sensor capable of measuring a first physical quantity of an object to be measured and a second sensor capable of measuring the first physical quantity of the object to be measured or a second physical quantity correlated with the first physical quantity, the calibration method comprising: a first measurement step of placing the first sensor on a first path through which the object to be measured flows and measuring the first physical quantity of the object to be measured with the first sensor; a second measurement step of placing the second sensor in a measurement environment less prone to deterioration than the first sensor and measuring the first physical quantity of the object to be measured or the second physical quantity with the second sensor; and a calibration step of calibrating the first sensor using the measured value of the first sensor and the measured value of the second sensor.

[0014] According to the material quantity measuring device, calibration program, and calibration method of the present invention, it becomes possible to reduce the frequency of manual calibration.

[0015] This is a schematic diagram showing a material quantity measuring device according to this embodiment. This is a schematic diagram showing the first measuring member and the second measuring member according to this embodiment. This is a schematic diagram showing an example of a measurement environment that is less prone to deterioration. This is a diagram showing the process of correcting the calibration curve.

[0016] Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. Note that the following embodiments are not intended to limit the invention as defined in each claim, and not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, in these embodiments, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[0017] [Overall Configuration of the Volume Measuring Device] As shown in Figure 1, the volume measuring device 1 comprises a first measuring member 100 and a second measuring member 200 capable of measuring a first volume value of a liquid (object to be measured), and a device body 300 connected to the first measuring member 100 and the second measuring member 200. The first measuring member 100 and the device body 300 are electrically connected via a first wiring W1. The second measuring member 200 and the device body 300 are electrically connected via a second wiring W2. Note that the connection may be made wirelessly instead of using the first wiring W1 and the second wiring W2. In addition, the volume measuring device 1 may have a third measuring member in addition to the first measuring member 100 and the second measuring member 200, and this third measuring member may be used as a spare measuring member.

[0018] [Configuration of the First Measuring Member] As shown in Figure 2, the first measuring member 100 comprises a first rod member 110 attached to the tip of the first wiring W1, a first sensor 120 attached to the tip of the first rod member 110, and a first flow cell 130 capable of housing the first rod member 110 and the first sensor 120. Note that the first rod member 110 is not an essential component of the first measuring member 100, and other configurations may be adopted as long as the first sensor 120 can be positioned on the first path R1, which will be described later.

[0019] The first sensor 120 is an electrode attached to the tip of the first rod member 110 and has a first working electrode 121 and a first reference electrode 122. The first working electrode 121 and the first reference electrode 122 are electrically connected to the device body 300 via a first wiring W1 attached to the first rod member 110. For example, a silver / silver chloride electrode can be used as the first working electrode 121. For example, a platinum electrode can be used as the first reference electrode 122.

[0020] The first sensor 120 is configured to measure a first physical quantity of the liquid to be measured. Specifically, the first sensor 120 is positioned on a first path R1 through which the liquid to be measured flows, and is configured to measure a voltage value corresponding to the residual chlorine concentration of the liquid to be measured as the first physical quantity. The first path R1 will be described later.

[0021] The first sensor 120 may have a counter electrode in addition to the first working electrode 121 and the first reference electrode 122. Furthermore, the first sensor 120 may be a sensor other than an electrode.

[0022] The first flow cell 130 has a first housing section 131 capable of housing the first rod member 110 and the first sensor 120, a first upstream connection section 132 that can be connected to a first flow path F1 provided upstream of the first measuring member 100, and a first downstream connection section 133 that can be connected to a second flow path F2 provided downstream of the first measuring member 100.

[0023] The first housing section 131 is formed in a long cylindrical shape having a first housing space 131a capable of housing the first rod member 110 and the first sensor 120. A first insertion opening 131b for passing the first wiring W1 is formed at the upper end of the first housing section 131. The first housing section 131 only needs to be configured to accommodate at least the first sensor 120, and if a configuration is adopted to replace the first rod member 110, it may have a shape corresponding to the shape of the adopted configuration.

[0024] The first upstream connection portion 132 is formed in a cylindrical shape having a first upstream flow space 132a that allows the liquid to be measured to flow, and extends from near the closed end (the other end in the longitudinal direction) of the first housing portion 131 toward the outside in the short direction of the first housing portion 131. A first inlet 132b is formed at the tip of the first upstream connection portion 132 for allowing the liquid to be measured to flow into the first upstream flow space 132a. At the base end of the first upstream connection portion 132, the first upstream flow space 132a is in communication with the first housing space 131a.

[0025] The first downstream connection portion 133 is formed in a cylindrical shape having a first downstream flow space 133a that allows the liquid to be measured to flow, and extends from the longitudinal center of the first housing portion 131 outward in the short direction of the first housing portion 131. A first outlet 133b is formed at the tip of the first downstream connection portion 133 for allowing the liquid to be measured to flow out from the first downstream flow space 133a. At the base end of the first downstream connection portion 133, the first downstream flow space 133a is in communication with the first housing portion 131a.

[0026] The first downstream connection portion 133 is preferably located higher than the first upstream connection portion 132, from the viewpoint of releasing air bubbles on the first path R1 and improving the measurement accuracy of the first sensor 120, but is not limited to this.

[0027] In the first flow cell 130 having the above configuration, the liquid to be measured that flows in from the first inlet 132b flows through the first upstream flow space 132a, the first containment space 131a, and the first downstream flow space 133a, and then flows out from the first outlet 133b (see arrow in Figure 2). That is, in the first flow cell 130 according to this embodiment, the first upstream flow space 132a, the first containment space 131a, and the first downstream flow space 133a constitute a first path R1 through which the liquid to be measured flows.

[0028] The first flow cell 130 is configured to position the first sensor 120 on the first path R1 by housing the first sensor 120 in the first accommodation space 131a.

[0029] [Configuration of the second measuring member] As shown in Figure 2, the second measuring member 200 is provided downstream of the first measuring member 100. The second measuring member 200 basically has the same configuration as the first measuring member 100. Specifically, as shown in Figure 2, the second measuring member 200 includes a second rod member 210 attached to the tip of the second wiring W2, a second sensor 220 attached to the tip of the second rod member 210, and a second flow cell 230 capable of housing the second rod member 210 and the second sensor 220. Note that the second rod member 210 is not an essential component of the second measuring member 200, and other configurations may be adopted as long as the second sensor 220 can be positioned on the second path R2, which will be described later.

[0030] The second sensor 220 is an electrode attached to the tip of the second rod member 210 and has a second working electrode 221 and a second reference electrode 222. The second working electrode 221 and the second reference electrode 222 are electrically connected to the device body 300 via a second wiring W2 attached to the second rod member 210. For example, a silver / silver chloride electrode can be used as the second working electrode 221. For example, a platinum electrode can be used as the second reference electrode 222.

[0031] The second sensor 220 is configured to measure a first physical quantity of the liquid to be measured. Specifically, the second sensor 220 is positioned on a second path R2 through which the liquid to be measured flows, and is configured to measure a voltage value corresponding to the residual chlorine concentration of the liquid to be measured as the first physical quantity. The second path R2 will be described later.

[0032] The second sensor 220 may have a counter electrode in addition to the second working electrode 221 and the second reference electrode 222. Furthermore, the second sensor 220 may be a sensor other than an electrode.

[0033] The second flow cell 230 includes a second housing section 231 capable of housing the second rod member 210 and the second sensor 220, a second upstream connection section 232 connectable to a second flow path F2 provided upstream of the second measuring member 200, and a second downstream connection section 233 connectable to a third flow path F3 provided downstream of the second measuring member 200.

[0034] The second housing section 231 is formed in a long cylindrical shape having a second housing space 231a capable of housing the second rod member 210 and the second sensor 220. A second insertion opening 231b for passing the second wiring W2 is formed at the upper end of the second housing section 231. The second housing section 231 only needs to be configured to accommodate at least the second sensor 220, and if a configuration is adopted to replace the second rod member 210, it may have a shape corresponding to the shape of the adopted configuration.

[0035] The second upstream connection portion 232 is formed in a cylindrical shape having a second upstream flow space 232a that allows the liquid to be measured to flow, and extends from near the closed end (the other end in the longitudinal direction) of the second housing portion 231 toward the outside in the short direction of the second housing portion 231. A second inlet 232b is formed at the tip of the second upstream connection portion 232 for allowing the liquid to be measured to flow into the second upstream flow space 232a. At the base end of the second upstream connection portion 232, the second upstream flow space 232a is in communication with the second housing space 231a.

[0036] The second downstream connection portion 233 is formed in a cylindrical shape having a second downstream flow space 233a that allows the liquid to be measured to flow, and extends from the longitudinal center of the second housing portion 231 outward in the short direction of the second housing portion 231. A second outlet 233b is formed at the tip of the second downstream connection portion 233 for allowing the liquid to be measured to flow out from the second downstream flow space 233a. At the base end of the second downstream connection portion 233, the second downstream flow space 233a is in communication with the second housing space 231a.

[0037] The second downstream connection portion 233 is preferably located higher than the second upstream connection portion 232, from the viewpoint of releasing air bubbles on the second path R2 and improving the measurement accuracy of the second sensor 220, but is not limited to this.

[0038] In the second flow cell 230 having the above configuration, the liquid to be measured that flows in from the second inlet 232b flows through the second upstream flow space 232a, the second containment space 231a, and the second downstream flow space 233a, and then flows out from the second outlet 233b (see arrow in Figure 2). In other words, in the second flow cell 230 according to this embodiment, the second upstream flow space 232a, the second containment space 231a, and the second downstream flow space 233a constitute a second path R2 through which the liquid to be measured flows.

[0039] The second flow cell 230 is configured to position the second sensor 220 on the second path R2 by housing the second sensor 220 in the second housing space 231a.

[0040] <Placement of the second sensor> In this embodiment, the second sensor 220 is placed in a measurement environment that is less prone to deterioration than the first sensor 120. Examples of measurement environments that are less prone to deterioration are given below, but are not limited to these. In this specification, "deterioration" is a term that includes deterioration due to dirt, scratches, wear, etc., as well as deterioration due to aging.

[0041] An example of a measurement environment that is less prone to degradation is an environment in which the second sensor 220 is configured to be switchable between a measurement state and a non-measurement state, and the measurement interval for the second sensor 220 is configured to be longer than the measurement interval for the first sensor 120. In the non-measurement state, oxidation-reduction reactions due to contact with the liquid to be measured do not occur, making it less prone to degradation. Since the second sensor 220 is in the non-measurement state for a longer period than the first sensor 120, it is less prone to degradation than the first sensor 120. A method for switching the second sensor 220 between the measurement state and the non-measurement state is, for example, by turning the electrical connection between the second sensor 220 and the main body of the device 300 on and off. The switching between the measurement state and the non-measurement state may be performed automatically or manually at a predetermined timing or at an arbitrary timing. The predetermined timing may be a predefined timing or a timing derived using a trained model. Machine learning may also be continued without using a trained model.

[0042] Another example of a measurement environment that is less prone to degradation is one in which the cross-sectional area of ​​the space where the second sensor 220 is located is larger than the cross-sectional area of ​​the space where the first sensor 120 is located. In this case, the flow velocity of the liquid to be measured flowing through the space where the second sensor 220 is located is slower than that of the liquid to be measured flowing through the space where the first sensor 120 is located. In other words, the amount of chlorine that comes into contact with the second sensor 220 is less than the amount of chlorine that comes into contact with the first sensor 120, so the second sensor 220 is less prone to degradation than the first sensor 120.

[0043] As yet another example of a measurement environment that is less prone to deterioration, as shown in FIG. 3, an environment is provided in which a switching unit 400 capable of switching between a flowing state in which a measurement target liquid flows through the second path R2 and a non-flowing state in which the measurement target liquid does not flow through the second path R2 is provided between the first path R1 and the second path R2. Specifically, the second flow path F2 is composed of a second flow path F2a connected to the first downstream connection portion 133 and a second flow path F2b branched from the second flow path F2a and connected to the second upstream connection portion 232, and the switching unit 400 is provided at the branch point of the second flow path F2a and the second flow path F2b. In this case, the flowing state can be set only when the measurement is performed by the second sensor 220, and the non-flowing state can be set when the measurement is not performed by the second sensor 220. Since the measurement interval for the second sensor 220 can be made longer than the measurement interval for the first sensor 120, the second sensor 220 is less prone to deterioration than the first sensor 120. As the switching unit 400, for example, a known valve can be used. The switching by the switching unit 400 may be performed automatically or manually at a predetermined timing or an arbitrary timing. The predetermined timing may be a pre-defined timing or a timing derived using a learned model. Machine learning may be continued without using a learned model.

[0044] As yet another example of a measurement environment that is less prone to deterioration, an environment is provided in which water is mixed into the measurement target liquid flowing into the second inlet 232b to dilute it. In this case, since the residual chlorine concentration of the measurement target liquid flowing through the second path R2 is lower than that of the measurement target liquid flowing through the first path R1, the second sensor 220 is less prone to deterioration than the first sensor 120.

[0045] Note that the measurement environment that is less prone to deterioration may be any one of the measurement environments exemplified above, or may be an environment in which any two or more of the measurement environments exemplified above are combined.

[0046] [Configuration of the Apparatus Main Body] As shown in FIG. 1, the apparatus main body 300 includes a control unit 310 having at least a CPU, a storage unit 320 having at least a RAM and a ROM, and a display unit 330 for displaying various information.

[0047] The control unit 310 includes a calculation unit 311 that calculates the residual chlorine concentration of the measurement target liquid using the measurement value of the first sensor 120, and a calibration unit 312 that calibrates the first sensor 120 using the measurement value of the first sensor 120 and the measurement value of the second sensor 220. Then, the control unit 310 develops the measurement program and the calibration program stored in the ROM in the RAM, and configures the CPU to interpret and execute these programs, so as to realize the functions of the calculation unit 311 and the calibration unit 312 described below.

[0048] Here, the measurement program is a program that causes the material quantity measuring device 1 to execute a first measurement process for measuring the first material quantity value of the measurement target liquid by the first sensor 120 disposed on the first path R1 through which the measurement target liquid flows, and a calculation process for calculating the residual chlorine concentration of the measurement target liquid using the measurement value of the first sensor 120. The calibration program is a program that causes the material quantity measuring device to execute a first measurement process for measuring the first material quantity value of the measurement target liquid by the first sensor 120 disposed on the first path R1 through which the measurement target liquid flows, a second measurement process for measuring the first material quantity value of the measurement target liquid by the second sensor 220 disposed in a measurement environment less prone to deterioration than the first sensor 120, and a calibration process for calibrating the first sensor 120 using the measurement value of the first sensor 120 and the measurement value of the second sensor 220.

[0049] The calculation unit 311 is configured to calculate the residual chlorine concentration of the measurement target liquid using the voltage value measured by the first sensor 120. Specifically, the calculation unit 311 is configured to calculate the residual chlorine concentration of the measurement target liquid based on the voltage value measured by the first sensor 120 and the calibration curve C showing the relationship between the residual chlorine concentration and the voltage. The calibration curve C is stored in the storage unit 320 in advance and can be corrected by the calibration unit 312 as described later.

[0050] The calibration unit 312 is configured to calibrate the first sensor 120 using the voltage value measured by the first sensor 120 and the voltage value measured by the second sensor 220. As described above, in this embodiment, the second sensor 220 is located in a measurement environment that is less prone to degradation than the first sensor 120, and therefore has higher measurement accuracy than the first sensor 120. For this reason, the calibration unit 312 can calibrate the first sensor 120 by using the measured value of the second sensor 220 as a reference value.

[0051] Specifically, as shown in Figure 4, the calibration unit 312 is configured to calculate the residual chlorine concentration of the liquid to be measured using the voltage value measured by the second sensor 220, and to correct the calibration curve C stored in the storage unit 320 based on the calculated residual chlorine concentration and the voltage value measured by the first sensor 120 (see calibration curve C' in Figure 4). The calculation of residual chlorine concentration by the calibration unit 312 is performed based on the voltage value measured by the second sensor 220 and a calibration curve that shows the relationship between residual chlorine concentration and voltage, similar to the calculation unit 311. Note that the calibration curve C used in the calculation unit 311 is data related to the first sensor 120, and the calibration curve used in the calibration unit 312 is data related to the second sensor 220.

[0052] The display unit 330 is a display and is configured to show various information, such as the residual chlorine concentration of the liquid to be measured calculated by the calculation unit 311 and the correction value calculated by the calibration unit 312.

[0053] [Measurement Method and Calibration Method] Next, the measurement method and calibration method using the material quantity measuring device 1 will be described.

[0054] <Preparation> The user connects the first measuring member 100 and the second measuring member 200 of the volume measuring device 1 to the flow path through which the liquid to be measured flows. Specifically, as shown in Figure 2, the first upstream connection part 132 of the first measuring member 100 is connected to the first flow path F1, and the first downstream connection part 133 of the first measuring member 100 is connected to the second flow path F2. In addition, the second upstream connection part 232 of the second measuring member 200 is connected to the second flow path F2, and the second downstream connection part 233 of the second measuring member 200 is connected to the third flow path F3. As a result, the liquid to be measured flows through the first flow path F1, the first path R1, the second flow path F2, the second path R2, and the third flow path F3.

[0055] <Measurement Method> First, the first sensor 120 of the first measuring member 100 measures a voltage value corresponding to the residual chlorine concentration of the liquid to be measured. Specifically, when the first working electrode 121 and the first reference electrode 122 of the first sensor 120 come into contact with the liquid to be measured, a voltage corresponding to the residual chlorine concentration of the liquid to be measured is generated between the first working electrode 121 and the first reference electrode 122 by an oxidation-reduction reaction, and this value is measured. Next, the calculation unit 311 of the main body of the device 300 calculates the residual chlorine concentration of the liquid to be measured based on the voltage value measured by the first sensor 120 and a calibration curve C that shows the relationship between residual chlorine concentration and voltage. The residual chlorine concentration of the liquid to be measured calculated by the calculation unit 311 is displayed on the display unit 330 of the main body of the device 300. Note that the measurement by the first sensor 120 may be performed continuously or intermittently at predetermined intervals. One method for intermittently performing measurements using the first sensor 120 is to switch the electrical connection between the first sensor 120 and the main unit 300 on and off. This on / off switching may be performed automatically or manually at a predetermined timing or at any timing. The predetermined timing may be a predefined timing or a timing derived using a trained model. Machine learning may also be continued without using a trained model.

[0056] <Calibration Method> First, the first sensor 120 of the first measuring member 100 and the second sensor 220 of the second measuring member 200 each measure a voltage value corresponding to the residual chlorine concentration of the liquid to be measured (first measurement step and second measurement step). The measurement configuration of the voltage value by the second sensor 220 is the same as that of the first sensor 120, so the explanation is omitted. Next, the calibration unit 312 of the main body of the device 300 corrects the calibration curve C stored in the memory unit 320 using the voltage value measured by the first sensor 120 and the residual chlorine concentration calculated using the voltage value measured by the second sensor 220 (calibration step).

[0057] [Advantages of the volume measuring device according to this embodiment] As described above, the volume measuring device 1 according to this embodiment includes a first sensor 120 capable of measuring a first volume value of a liquid to be measured (object to be measured), a second sensor 220 capable of measuring a first volume value of a liquid to be measured, and a calibration unit 312 that calibrates the first sensor 120 using the measured value of the first sensor 120 and the measured value of the second sensor 220. The first sensor 120 is positioned on a first path R1 through which the liquid to be measured flows, and the second sensor 220 is positioned in a measurement environment that is less prone to deterioration than the first sensor 120.

[0058] With the volume measuring device 1 having this configuration, since the first sensor 120 is located on the first path R1, the liquid being measured is the same or approximately the same each time. Therefore, the calibration frequency of the first sensor 120 can be reduced from the outset. Furthermore, with the volume measuring device 1 having the above configuration, the first sensor 120 can be automatically calibrated using the voltage value of the first sensor 120 and the residual chlorine concentration of the second sensor 220. This reduces the frequency of manual calibration and allows calibration to be performed without removing the first sensor 120 from the first path R1, thus significantly reducing the burden on the user during calibration. For example, if the first sensor 120 had to be manually calibrated every 40 measurements, then if five measurements were taken per day, calibration would have to be performed every eight days. If manual calibration is performed using the second sensor 220, and the second sensor 220 also needs to be manually calibrated every 40 measurements, then the second sensor 220 will need to be manually calibrated when the number of measurements of the first sensor 120 reaches 40 x 40 = 1600. In other words, using this method, the manual calibration of the first sensor 120, which is performed once every 8 days, can be replaced with calibration using the second sensor 220, reducing the frequency of manual calibration to once every 320 days (1600 measurements ÷ 5 measurements / day = 320 days, approximately once a year). (In this case, manual calibration may be performed only on the second sensor 220, or on both the first sensor 120 and the second sensor 220). Furthermore, if the first sensor 120 only needs to be calibrated every 3 months instead of every 8 days, the frequency of manual calibration can be reduced even further.

[0059] Furthermore, with the above-described material quantity measuring device 1, the second sensor 220 is placed in a measurement environment that is less prone to deterioration than the first sensor 120, and the measurement accuracy is higher than that of the first sensor 120. Therefore, the first sensor 120 can be calibrated based on the measurement value of the second sensor 220. As a result, highly accurate measurement and calibration can be achieved without using expensive, high-precision sensors as the first sensor 120 and the second sensor 220. In other words, inexpensive, low-precision sensors can be used as the first sensor 120 and the second sensor 220, thereby reducing costs.

[0060] In a volume measuring device 1 according to an example of this embodiment, the second sensor 220 is positioned on a second path R2 through which the liquid to be measured flows. The second sensor 220 is configured to be switchable between a measurement state and a non-measurement state, and the measurement interval for the second sensor 220 is configured to be longer than the measurement interval for the first sensor 120. With a volume measuring device 1 having such a configuration, since the measurement interval for the second sensor 220 is longer than the measurement interval for the first sensor 120, the wear of the second sensor 220 can be reduced compared to that of the first sensor 120. In other words, the second sensor 220 can be placed in a measurement environment that is less prone to deterioration than that of the first sensor 120.

[0061] In another example of this embodiment, the volume measuring device 1 is positioned on a second path R2 through which the liquid to be measured flows, and the cross-sectional area of ​​the space in which the second sensor 220 is located is larger than the cross-sectional area of ​​the space in which the first sensor 120 is located. With a volume measuring device 1 having such a configuration, because the cross-sectional area of ​​the space in which the second sensor 220 is located is larger than the cross-sectional area of ​​the space in which the first sensor 120 is located, the flow velocity of the liquid to be measured flowing through the space in which the second sensor 220 is located can be made slower than that of the liquid to be measured flowing through the space in which the first sensor 120 is located. As a result, the amount of contact between the second sensor 220 and substances in the liquid to be measured that cause sensor wear is lower compared to the first sensor 120, so that the second sensor 220 can be placed in a measurement environment that is less prone to deterioration than the first sensor 120.

[0062] In yet another example of this embodiment, the volume measuring device 1 is positioned on a second path R2 through which the liquid to be measured flows. Between the first path R1 and the second path R2, there is a switching unit 400 that can switch between a flowing state in which the liquid to be measured flows in the second path R2 and a non-flowing state in which the liquid to be measured does not flow in the second path R2. With a volume measuring device 1 having such a configuration, the flowing state can be set only when measurement is performed by the second sensor 220, and the non-flowing state can be set when measurement is not performed by the second sensor 220. This allows the measurement interval for the second sensor 220 to be longer than the measurement interval for the first sensor 120, so that the second sensor 220 can be placed in a measurement environment that is less prone to deterioration than the first sensor 120.

[0063] The quantity measuring device 1 according to this embodiment includes a first flow cell 130 capable of housing a first sensor 120 and a second flow cell 230 capable of housing a second sensor 220. With the quantity measuring device 1 having such a configuration, the first sensor 120 can be positioned on the first path R1 and the second sensor 220 can be positioned on the second path R2.

[0064] [Modifications] The material quantity measuring device, calibration program, and calibration method according to the present invention are not limited to the embodiments described above, and various modifications and combinations can be made without departing from the technical concept of the present invention.

[0065] In the embodiments described above, the object to be measured was assumed to be a liquid (measurement target liquid), but the invention is not limited to this. Therefore, as the first sensor 120 and the second sensor 220, various sensors can be used depending on the object to be measured, as long as they are sensors that require calibration, such as the electrodes in the embodiments described above.

[0066] In the embodiment described above, a configuration was described in which the first sensor 120 measures a voltage value and the calculation unit 311 calculates the residual chlorine concentration of the liquid to be measured using the voltage value measured by the first sensor 120. However, the system is not limited to this configuration, and the first sensor 120 may measure a current value corresponding to the residual chlorine concentration of the liquid to be measured, and the calculation unit 311 may calculate the residual chlorine concentration of the liquid to be measured using the current value measured by the first sensor 120. In other words, measurement may be performed using a so-called polarographic method instead of a so-called galvanic method.

[0067] In the embodiment described above, a configuration was described in which the second sensor 220 measures a first physical value of the liquid to be measured. However, the invention is not limited to this, and a configuration is also provided in which a second physical value correlated with the first physical value is measured. In the embodiment described above, the first physical value is a voltage value corresponding to the residual chlorine concentration of the liquid to be measured. The second physical value correlated with such a first physical value is, for example, a current value corresponding to the residual chlorine concentration of the liquid to be measured.

[0068] In the embodiment described above, the first sensor 120 and the second sensor 220 are electrodes, and the calculation unit 311 calculates the residual chlorine concentration of the liquid to be measured using the measurement value of the first sensor 120. However, the embodiment is not limited to this, and the calculation unit 311 may be configured to calculate other quantitative values ​​of the liquid to be measured, and the first sensor 120 and the second sensor 220 may be other sensors corresponding to the quantitative values ​​calculated by the calculation unit 311. For example, optical sensors or acoustic sensors may be used as the first sensor 120 and the second sensor 220. Such optical sensors and acoustic sensors, like electrodes, are susceptible to deterioration due to dirt, scratches, wear, and aging, and require calibration, making them valuable as the first sensor 120 and the second sensor 220.

[0069] In the embodiments described above, as an example of a measurement environment that is less prone to deterioration, a configuration in which the switching unit 400 is provided between the first path R1 and the second path R2, that is, a configuration in which it is provided between the first flow cell 130 and the second flow cell 230, was explained. However, the invention is not limited to this, and the first flow cell 130 and the second flow cell 230 may be arranged in parallel, with the switching unit 400 provided upstream of the first flow cell 130 and the second flow cell 230.

[0070] In the above-described embodiment, the material quantity measuring device 1 is provided with a first flow cell 130 and a second flow cell 230, and the first flow cell 130 and the second flow cell 230 are provided with a first path R1 and a second path R2, respectively. However, the invention is not limited to this configuration, and the material quantity measuring device 1 may not be provided with a first flow cell 130 and a second flow cell 230, and the first sensor 120 and the second sensor 220 may be directly attached to the flow path. In other words, the flow path may be part of the configuration of the material quantity measuring device 1 and function as the first path R1 and the second path R2.

[0071] In the above-described embodiment, a configuration was explained in which the calibration unit 312 corrects the calibration curve C showing the relationship between residual chlorine concentration and voltage. However, the invention is not limited to this, and the calibration curve can be corrected according to the type of sensor applied to the first sensor 120 and the second sensor 220.

[0072] In the embodiment described above, a configuration was described in which the second measuring member 200 is provided downstream of the first measuring member 100. However, the invention is not limited to this configuration, and the second measuring member 200 may be provided upstream of the first measuring member 100.

[0073] In the above-described embodiment, a method for correcting the calibration curve C was explained as a calibration method for the first sensor 120. However, the invention is not limited to this, and for example, the calibration unit 312 may use the voltage value measured by the first sensor 120 and the voltage value measured by the second sensor 220 to calculate a correction value for correcting the voltage value measured by the first sensor 120, and the calculation unit 311 may use this correction value to correct the voltage value and then calculate the residual chlorine concentration. Examples of methods for calculating the correction value include calculating the difference between the voltage value measured by the first sensor 120 and the voltage value measured by the second sensor 220 as the correction value, or storing a calculation formula for calculating the correction value in the storage unit 320 in advance and calculating the correction value based on the voltage value measured by the first sensor 120, the voltage value measured by the second sensor 220, and the calculation formula stored in the storage unit 320.

[0074] Furthermore, the calibration by the calibration unit 312 may use various combinations, such as the residual chlorine concentration in the first sensor 120 and the residual chlorine concentration in the second sensor 220, the current value in the first sensor 120 and the residual chlorine concentration in the second sensor 220, or the current value in the first sensor 120 and the current value in the second sensor 220.

[0075] It is clear from the claims that the above-described modifications are included within the scope of the present invention.

[0076] 1: Material quantity measuring device 100: First measuring member 110: First rod member 120: First sensor 121: First working electrode 122: First reference electrode 130: First flow cell 131: First housing section 131a: First housing space 131b: First inlet 132: First upstream connection section 132a: First upstream flow space 132b: First inlet 133: First downstream connection section 133a: First downstream flow space 133b: First outlet 200: Second measuring member 210: Second rod member 220: Second sensor 221: Second working electrode 222: Second reference electrode 230 : Second flow cell 231 : Second housing section 231a : Second housing space 231b : Second inlet 232 : Second upstream connection section 232a : Second upstream flow space 232b : Second inlet 233 : Second downstream connection section 233a : Second downstream flow space 233b : Second outlet 300 : Main body of the device 310 : Control unit 311 : Calculation unit 312 : Calibration unit 320 : Storage unit 330 : Display unit 400 : Switching unit

Claims

1. A quantity measuring device comprising: a first sensor capable of measuring a first quantity of an object to be measured; a second sensor capable of measuring the first quantity of the object to be measured or a second quantity correlated with the first quantity; and a calibration unit that calibrates the first sensor using the measurement values ​​of the first sensor and the second sensor, wherein the first sensor is positioned on a first path through which the object to be measured flows, and the second sensor is positioned in a measurement environment less susceptible to deterioration than the first sensor.

2. The material quantity measuring device according to claim 1, wherein the second sensor is positioned on a second path through which the object to be measured flows, the second sensor is configured to be switchable between a measurement state and a non-measurement state, and the measurement interval for the second sensor is configured to be longer than the measurement interval for the first sensor.

3. The material quantity measuring device according to claim 1, wherein the second sensor is positioned on a second path through which the object to be measured flows, and the cross-sectional area of ​​the space in which the second sensor is located is greater than the cross-sectional area of ​​the space in which the first sensor is located.

4. The material quantity measuring device according to claim 1, wherein the second sensor is positioned on a second path through which the object to be measured flows, and a switching unit is provided between the first path and the second path that can switch between a flowing state in which the object to be measured flows in the second path and a non-flowing state in which the object to be measured does not flow in the second path.

5. A material quantity measuring device according to any one of claims 1 to 4, comprising a first flow cell capable of housing the first sensor and a second flow cell capable of housing the second sensor.

6. The material quantity measuring device according to any one of claims 1 to 4, wherein the first sensor and the second sensor each have a working electrode and a reference electrode, and the working electrode is a silver / silver chloride electrode.

7. A calibration program that causes a material quantity measuring device, comprising a first sensor capable of measuring a first material quantity of an object to be measured, and a second sensor capable of measuring the first material quantity of the object to be measured or a second material quantity correlated with the first material quantity, to perform a calibration process to calibrate the first sensor, the calibration program causing the material quantity measuring device to perform: a first measurement process of measuring the first material quantity of the object to be measured using the first sensor placed on a first path through which the object to be measured flows; a second measurement process of measuring the first or second material quantity of the object to be measured using the second sensor placed in a measurement environment less prone to deterioration than the first sensor; and a calibration process of calibrating the first sensor using the measured values ​​of the first sensor and the second sensor.

8. A calibration method for calibrating a first sensor using a first sensor capable of measuring a first physical quantity of an object to be measured, and a second sensor capable of measuring the first physical quantity of the object to be measured or a second physical quantity correlated with the first physical quantity, the calibration method comprising: a first measurement step of placing the first sensor on a first path through which the object to be measured flows and measuring the first physical quantity of the object to be measured with the first sensor; a second measurement step of placing the second sensor in a measurement environment less prone to deterioration than the first sensor and measuring the first physical quantity or the second physical quantity of the object to be measured with the second sensor; and a calibration step of calibrating the first sensor using the measured value of the first sensor and the measured value of the second sensor.

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