Calibration device, calibration method, and calibration program

Abstract

To reduce the time required to calibrate multiple pH sensors.SOLUTION: A calibration device 10 provided herein calibrates a pH sensor CS-1 for measuring pH of an aqueous solution, calibrates a pH sensor CS-2 different from the pH sensor CS-1, and provides control to enable concurrent calibration of the pH sensor CS-1 and the pH sensor CS-2 if the pH sensor CS-1 and the pH sensor CS-2 are immersed in a pH standard solution having a given pH.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a calibration device, a calibration method, and a calibration program. [Background technology]

[0002] A pH sensor is a sensor that measures the pH (hydrogen ion exponent) value of a target aqueous solution. A well-known measurement method for pH sensors is the glass electrode method. The glass electrode method utilizes the proportional relationship between the potential difference between two electrodes inside the pH sensor and the pH value of the target being measured. Measuring pH using this method requires periodic calibration by the operator. At this time, the operator performs calibration using a pH standard solution with a known pH value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-188819 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-228139 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is difficult to reduce the time required to calibrate multiple pH sensors. For example, in conventional techniques, when calibrating multiple pH sensors, each pH sensor is calibrated individually, which requires time proportional to the number of pH sensors.

[0005] The present invention has been made in view of the above, and is capable of shortening the time required to calibrate a plurality of pH sensors. [Means for solving the problem]

[0006] A calibration device according to one embodiment of the present invention comprises a first calibration unit that calibrates a first pH sensor that measures the pH of an aqueous solution, a second calibration unit that calibrates a second pH sensor that is different from the first pH sensor, and a calibration management unit that manages the calibration of the first pH sensor and the second pH sensor so that they can be performed in parallel when both the first pH sensor and the second pH sensor are immersed in a pH standard solution that exhibits a predetermined pH.

[0007] A calibration method according to one embodiment of the present invention involves a computer executing a process in which the computer calibrates a first pH sensor that measures the pH of an aqueous solution, calibrates a second pH sensor that is different from the first pH sensor, and, when the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, manages the calibration of the first pH sensor and the second pH sensor so that they can be performed in parallel.

[0008] A calibration program according to one embodiment of the present invention causes a computer to execute a process of calibrating a first pH sensor that measures the pH of an aqueous solution, calibrating a second pH sensor that is different from the first pH sensor, and, when the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, managing the calibration of the first pH sensor and the second pH sensor so that they can be executed in parallel. [Effects of the Invention]

[0009] According to the present invention, it is possible to reduce the time required to calibrate a plurality of pH sensors. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of the configuration and processing of a pH sensor calibration system according to an embodiment; [Figure 2] FIG. 10 is a diagram for explaining the relationship between the potential difference between electrodes and pH in the pH sensor calibration system according to the reference technology. [Figure 3] 1A to 1C are diagrams for explaining each procedure of a pH sensor calibration system according to a reference technique. [Figure 4] 10A and 10B are diagrams for explaining the time variation of measured values ​​during calibration of a pH sensor calibration system according to the reference technology. [Figure 5] FIG. 2 is a block diagram showing an example of the configuration of each device of the pH sensor calibration system according to the embodiment. [Figure 6] 3A to 3C are diagrams showing specific examples of each procedure of the pH sensor calibration system according to the embodiment. [Figure 7] 3 is a flowchart showing an example of the processing flow of the pH sensor calibration system according to the embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of a hardware configuration according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] A calibration device, a calibration method, and a calibration program according to an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiment described below.

[0012] The following describes the configuration and processing of the pH sensor calibration system 100 according to the embodiment, the configuration and processing of each device of the pH sensor calibration system 100, the flow of each process of the pH sensor calibration system 100, and the effects of the embodiment.

[0013] 1. Configuration and Processing of pH Sensor Calibration System 100 1 to 4, the configuration and processing of a pH sensor calibration system 100 according to an embodiment will be described. Below, an example of the overall configuration of the pH sensor calibration system 100, the basic principles of the pH sensor calibration system 100, an example of processing by the pH sensor calibration system 100, and the effects of the pH sensor calibration system 100 will be described. Note that in the embodiment, a calibration device 10 that calibrates a pH sensor CS that measures pH will be described as an example, but the measurement target and field of use are not limited thereto.

[0014] (1-1. Example of the overall configuration of the pH sensor calibration system 100) Here, an example of the overall configuration of a pH sensor calibration system 100 will be described using FIG. 1. The pH sensor calibration system 100 is composed of a calibration device 10, pH sensors CS (CS-1, CS-2), and various liquids L (first cleaning liquid L1, zero-point buffer solution L2, second cleaning liquid L3, slope-point buffer solution L4). FIG. 1 is a diagram showing an example of the configuration and processing of the pH sensor calibration system 100 according to an embodiment. Here, the calibration device 10 and the pH sensor CS are connected via predetermined wiring. Furthermore, the calibration device 10 is communicably connected to various devices (not shown) via a predetermined communication network (not shown) via wired or wireless means. Note that the predetermined communication network can be any of various communication networks such as the Internet or a dedicated line.

[0015] (1-1-1. Calibration device 10) The calibration device 10 is operated by an operator W and is a device for calibrating a pH sensor CS. For example, the calibration device 10 is installed in a laboratory, a plant, or the like that handles the aqueous solution to be measured. The pH sensor calibration system 100 shown in FIG. 1 may include multiple calibration devices 10. In the example of FIG. 1, the calibration device 10 is implemented by a liquid analyzer converter, but the device is not particularly limited as long as it is a device that allows reference to analog values, similar to a liquid analyzer converter. The calibration device 10 may also be implemented by a desktop PC (Personal Computer), a laptop PC, a smartphone, a server device, a cloud system, or the like, via digital communication via a device that converts analog values ​​to digital values.

[0016] (1-1-2. pH sensor CS) The pH sensors CS (CS-1, CS-2) are sensors that measure the pH of an aqueous solution to be measured using the glass electrode method. For example, the pH sensors CS (CS-1, CS-2) measure the pH of different aqueous solutions and display the measured values ​​on the monitor of the calibration device 10.

[0017] (1-1-3. Worker W) The operator W is a manager of a laboratory, a plant, or the like that handles aqueous solutions to be measured, and operates the calibration device 10 to calibrate the pH sensors CS (CS-1, CS-2).

[0018] (1-1-4. Various liquids L) The various liquids L (first cleaning liquid L1, zero-point buffer solution L2, second cleaning liquid L3, slope point buffer solution L4) are liquids used by the operator W when calibrating the pH sensor CS. Here, the first cleaning liquid L1 is, for example, pure water, and is a liquid used to clean the pH sensor CS before zero-point calibration. The zero-point buffer solution L2 is, for example, a buffer solution near pH 7, and is a pH standard solution used to measure the offset value O. The second cleaning liquid L3 is, for example, pure water, and is a liquid used to clean the pH sensor CS before slope point calibration. The slope point buffer solution L4 is, for example, a buffer solution near pH 4, and is a pH standard solution used to measure the slope value S.

[0019] (1-2. Processing example of pH sensor calibration system 100) An example of processing of the pH sensor calibration system 100 will be described with reference to Figure 1. Below, a first cleaning process, a first calibration process, a second cleaning process, and a second calibration process will be described. Note that the following processes (1) to (4) can be executed in a different order. Also, some of the following processes (1) to (4) may be omitted.

[0020] (1-2-1. First cleaning process) First, the operator W uses a first cleaning liquid L1 to clean the first pH sensor CS-1 (simply referred to as "pH sensor CS-1" as appropriate) and the second pH sensor CS-2 (simply referred to as "pH sensor CS-2" as appropriate) (see FIG. 1(1)). For example, before calibrating the zero point, the operator W uses pure water as the first cleaning liquid L1 to clean the pH sensors CS-1 and CS-2. The operator W can also use tap water or a measurement liquid as the first cleaning liquid L1.

[0021] (1-2-2. First calibration process) Second, operator W calibrates pH sensors CS-1 and CS-2 using zero-point buffer solution L2 (see Figure 1(2)). For example, operator W calibrates pH sensors CS-1 and CS-2 in parallel using a neutral standard solution with a pH of around 7 as zero-point buffer solution L2.

[0022] First, operator W simultaneously immerses pH sensors CS-1 and CS-2 in the zero-point buffer solution L2 in the same container. Next, operator W waits for the zero-point measurements taken by pH sensors CS-1 and CS-2 to stabilize. Operator W then confirms that the zero-point measurements taken by pH sensors CS-1 and CS-2 have stabilized, and operates calibration device 10 to record the measurements. Here, calibration device 10 manages the zero-point calibration of both pH sensors CS-1 and CS-2 so that they can be performed in parallel.

[0023] (1-2-3. Second cleaning process) Third, the worker W uses the second cleaning liquid L3 to clean the pH sensors CS-1 and CS-2 (see FIG. 1(3)). For example, before the calibration of the slope point, the worker W uses pure water as the second cleaning liquid L3 to clean the pH sensors CS-1 and CS-2. The worker W can also use tap water or the measurement liquid as the second cleaning liquid L3.

[0024] (1-2-4. Second calibration process) Fourth, the operator W calibrates the pH sensors CS-1 and CS-2 using the slope point buffer solution L4 (see Figure 1(4)). For example, the operator W calibrates the pH sensors CS-1 and CS-2 in parallel using an acidic standard solution with a pH of around 4 as the slope point buffer solution L4.

[0025] First, operator W immerses pH sensors CS-1 and CS-2 in the slope point buffer solution L4 in the same container. Next, operator W waits for the slope point measurements taken by pH sensors CS-1 and CS-2 to stabilize. Operator W then confirms that the slope point measurements taken by pH sensors CS-1 and CS-2 have stabilized, and operates calibration device 10 to record the measurements. Here, calibration device 10 manages the calibration so that two slope point calibrations can be performed in parallel for each of pH sensors CS-1 and CS-2.

[0026] (1-2-5. Other) 1(1) to 1(4) illustrate an example of a process in which a neutral standard solution and an acidic standard solution are used in that order for two-point calibration of the pH sensor CS. However, the type and order of the pH standard solutions are not particularly limited. For example, in the pH sensor calibration system 100, the calibration device 10 can select and use two pH standard solutions from a neutral standard solution, an acidic standard solution, and a basic standard solution. Furthermore, in the pH sensor calibration system 100, the calibration device 10 can use the two selected pH standard solutions in any order for calibration. Furthermore, in the pH sensor calibration system 100, the calibration device 10 does not need to select pH standard solutions of different pHs. As long as an appropriate calibration curve can be created, the calibration device 10 can also select two neutral standard solutions with different pHs, two acidic standard solutions with different pHs, or two basic standard solutions with different pHs.

[0027] 1(1) to 1(4) have been described as an example of processing in which two-point calibration of two pH sensors CS is performed in parallel, but the number of pH sensors CS and the type of calibration are not particularly limited. For example, in the pH sensor calibration system 100, the calibration device 10 can manage three or more pH sensors CS so that their respective calibrations can be performed in parallel. In the pH sensor calibration system 100, the calibration device 10 can also employ one-point calibration or three-point calibration as a type of calibration.

[0028] (1-3. Overview and Problems of pH Sensor Calibration System 100P) Below, an overview and problems of a pH sensor calibration system 100P according to the reference technology will be described.

[0029] (1-3-1. Overview of pH Sensor Calibration System 100P) 2 to 4 and equations, an overview of a pH sensor calibration system 100P according to the reference technology will be described. Below, the calibration principle, calibration procedure, and time variation of the measurement value during calibration of the pH sensor calibration system 100P will be described.

[0030] (1-3-1-1. Calibration principle) The calibration principle of the pH sensor calibration system 100P according to the reference technology will be explained using Figure 2 and mathematical formulas. Figure 2 is a diagram for explaining the relationship between the potential difference between the electrodes of the pH sensor calibration system 100P according to the reference technology and pH. Below, the basic principle of the pH sensor CS, a specific example of a calibration curve, and the basic principle of two-point calibration will be explained.

[0031] (Basic principle of pH sensor CS) First, we will explain the basic principle of the pH sensor CS. The pH sensor CS is a sensor that measures the pH value of a target aqueous solution. The glass electrode method is known as a measurement method for the pH sensor CS. The glass electrode method is a measurement method that utilizes the proportional relationship between the potential difference between the two electrodes inside the pH sensor CS and the pH value of the target to be measured.

[0032] (Example of calibration curve) Second, a specific example of a calibration curve will be described. When measuring pH using the glass electrode method described above, the operator W must periodically calibrate the pH sensor CS. For example, in the case of two-point calibration described below, the operator W performs calibration using two types of pH standard solutions, such as buffer solutions, whose pH values ​​are known, and determines the calibration curve.

[0033] As shown by the dashed line in Figure 2, in the relationship between the potential difference between the electrodes and pH, the theoretical value is that when the solution is at 25°C, a difference of 1 in pH generates an electromotive force of 59.16 mV, and when the solution is at pH 7, the potential difference is 0 mV. On the other hand, the measured value differs from the theoretical value. Therefore, as shown by the solid line in Figure 2, operator W creates a calibration curve by calibrating at two or more points based on the proportional relationship between the pH value and the potential difference.

[0034] (Basic principle of two-point calibration) Third, we will explain the basic principles of two-point calibration. First, to calibrate the zero point, operator W immerses pH sensor CS in zero-point buffer solution L2 (a neutral standard solution with a pH of around 7) and measures the offset value O, which is the potential difference between the electrodes. Next, to calibrate the slope point, operator W immerses pH sensor CS in slope-point buffer solution L4 (an acidic standard solution with a pH of around 4) and measures the slope value S, which is the potential difference between the electrodes. Operator W then calculates the slope %SL (which indicates the sensitivity of pH sensor CS), which represents the degree of conformance with the theoretical value, from the offset value O and slope value S, and creates a calibration curve. The slope is calculated using the following equation (1).

[0035]

number

[0036] (1-3-1-2. Calibration procedure) The calibration procedure of the pH sensor calibration system 100P according to the reference technology will be described with reference to Fig. 3. Fig. 3 is a diagram for explaining each procedure of the pH sensor calibration system 100P according to the reference technology. Below, a specific example of the calibration device 10P of the pH sensor calibration system 100P according to the reference technology and the calibration procedure of the pH sensor calibration system 100P will be described.

[0037] (Calibration device 10P) First, the calibration device 10P will be described. The calibration device 10P has an HMI (Human Machine Interface) display function and a calibration function. The calibration device 10P can call up an independent calibration function for each pH sensor CS using the HMI display function. The calibration device 10P can also calibrate the pH sensors CS using the calibration function. For example, the calibration device 10P is connected to the pH sensors CS via serial communication, and can control the pH sensors CS, including calibrating them, through operations on the calibration device 10P by an operator W. The calibration device 10P also controls the pH sensors CS, including calibrating them, one by one.

[0038] (Example of calibration procedure) Second, a specific example of the calibration procedure will be described. First, as shown in FIG. 3(1), an operator W immerses the pH sensor CS in a first cleaning liquid L1, such as pure water, to clean the pH sensor CS (step P1). Next, as shown in FIG. 3(2), an operator W immerses the pH sensor CS in a zero-point buffer solution L2, which is a neutral standard solution (step P2), waits for the zero-point measurement value measured by the pH sensor CS to stabilize (step P3), and once the zero-point measurement value has stabilized, operates the calibration device 10P to record the measurement value (step P4). Furthermore, as shown in FIG. 3(3), an operator W immerses the pH sensor CS in a second cleaning liquid L3, such as pure water, to clean the pH sensor CS (step P5). Then, as shown in Figure 3(4), the operator W immerses the pH sensor CS in the slope point buffer solution L4, which is an acidic standard solution (step P6), waits for the slope point measurement value measured by the pH sensor CS to stabilize (step P7), and once the slope point measurement value has stabilized, operates the calibration device 10P to record the measurement value (step P8).

[0039] (1-3-1-3. Time variation of measured values ​​during calibration) Variation over time of measured values ​​during calibration by a pH sensor calibration system 100P according to the reference technology will be described using Fig. 4. Fig. 4 is a diagram for explaining variation over time of measured values ​​during calibration by a pH sensor calibration system 100P according to the reference technology. Below, measurement values ​​at times T1 to T6 will be described.

[0040] (Time T1) First, the measurement value at time T1 will be described. T1 in Fig. 4 indicates the measurement value before the start of calibration, when the pH sensor CS is immersed in the first cleaning liquid L1 such as pure water.

[0041] (Time T2) Second, the measurement value at time T2 will be explained. At time T2 in Fig. 4, the pH sensor CS is immersed in the zero-point buffer solution L2, which is a neutral standard solution (pH 6.8).

[0042] (Time T3) Third, the measurement value at time T3 will be described. T3 in Figure 4 is a state in which the zero-point measurement value measured by pH sensor CS is stable. At this time, operator W operates calibration device 10P to record the zero-point measurement value.

[0043] (Time T4) Fourth, the measurement value at time T4 will be described. At time T4 in Fig. 4, the pH sensor CS is removed from the zero-point buffer solution L2 and immersed in a second cleaning liquid L3 such as pure water.

[0044] (Time T5) Fifth, the measurement value at time T5 will be described. T5 in Fig. 4 is the state in which the pH sensor CS is immersed in the slope point buffer solution L4, which is an acidic standard solution (pH 4.0).

[0045] (Time T6) Sixth, the measurement value at time T6 will be described. T6 in Figure 4 is a state in which the measurement value of the slope point measured by the pH sensor CS is stable. At this time, the operator W operates the calibration device 10P to record the measurement value of the slope point.

[0046] (1-3-1-4. Other) The overview of the pH sensor calibration system 100P described above is for two-point calibration, but it is similar for three-point calibration, one-point calibration, etc. Below, the basic principles of three-point calibration and one-point calibration are explained.

[0047] (Basic principle of three-point calibration) First, to calibrate the zero point, operator W immerses pH sensor CS in zero-point buffer solution L2 (a neutral standard solution with a pH of around 7) and measures the offset value O, which is the potential difference between the electrodes. Next, to calibrate the slope point in the acidic region, operator W immerses pH sensor CS in slope point buffer solution L4 (an acidic standard solution with a pH of around 4) and measures the slope value S, which is the potential difference between the electrodes. To calibrate the slope point in the basic region, operator W immerses pH sensor CS in slope point buffer solution L5 (a basic standard solution with a pH of around 10) and measures the slope value S', which is the potential difference between the electrodes. Operator W then calculates the slope (%SL), which represents the degree of conformance to the theoretical value, from the offset value O, slope value S, and slope value S', and creates a calibration curve.

[0048] (Basic principle of one-point calibration) First, to calibrate the zero point, operator W immerses pH sensor CS in zero-point buffer solution L2 (neutral standard solution with a pH of around 7) and measures the offset value O, which is the potential difference between the electrodes. Then operator W creates a calibration curve from the offset value O and the theoretical value.

[0049] (1-3-2. Problems with the pH sensor calibration system 100P) The following describes the problems with the pH sensor calibration system 100P according to the reference technology. As explained above in (1-3-1-3. Variation in measurement values ​​over time during calibration), when performing two-point calibration of one pH sensor CS in the pH sensor calibration system 100P, the measurement value changes significantly, especially from time T5 to time T6, and it takes a long time for the measurement value to stabilize. Furthermore, in the pH sensor calibration system 100P, the calibration device 10P must calibrate each pH sensor CS one by one.

[0050] Therefore, the pH sensor calibration system 100P has the following problems. First, when the pH sensor calibration system 100P is used to calibrate two or more pH sensors CS, the time required is roughly proportional to the number of pH sensors CS compared to calibrating only one. Second, when the pH sensor calibration system 100P is used to calibrate two or more pH sensors CS, the labor required is greater compared to calibrating only one, which places a greater burden on the operator W. Third, when the pH sensor calibration system 100P is used to calibrate two or more pH sensors CS, the amount of pH standard solution required for calibration is greater compared to calibrating only one.

[0051] (1-4. Overview and Effects of the pH Sensor Calibration System 100) The outline and effects of the pH sensor calibration system 100 according to the embodiment will be described below.

[0052] (1-4-1. Overview of pH sensor calibration system 100) An overview of a pH sensor calibration system 100 according to an embodiment will be described. The pH sensor calibration system 100 performs the following processes. First, an operator W uses a first cleaning solution L1, such as pure water, to clean the pH sensors CS-1 and CS-2. Second, the operator W calibrates the pH sensors CS-1 and CS-2 in parallel using a zero-point buffer solution L2, which is a neutral standard solution. At this time, the calibration device 10 manages the calibration so that two zero-point calibrations of the pH sensors CS-1 and CS-2 can be performed in parallel. Third, the operator W uses a second cleaning solution L3, such as pure water, to clean the pH sensors CS-1 and CS-2. Fourth, the operator W calibrates the pH sensors CS-1 and CS-2 in parallel using a slope-point buffer solution L4, such as an acidic standard solution. At this time, the calibration device 10 manages the calibration so that two slope-point calibrations of the pH sensors CS-1 and CS-2 can be performed in parallel.

[0053] (1-4-2. Effects of the pH sensor calibration system 100) The effects of the pH sensor calibration system 100 according to the embodiment will be described. First, by managing the calibration device 10 so that the calibration of two or more pH sensors CS can be performed in parallel, i.e., simultaneously, there is an effect that the time required for calibration can be shortened. Second, by managing the calibration device 10 so that the calibration of two or more pH sensors CS can be performed in parallel, i.e., simultaneously, there is an effect that the labor required for calibration by the operator W, such as replacing various liquids L, can be reduced, and the burden on the operator W can be alleviated. Third, by managing the calibration device 10 so that the calibration of two or more pH sensors CS can be performed in parallel, i.e., simultaneously, there is an effect that the amount of pH standard solution used can be reduced, which is susceptible to pH fluctuations and difficult to reuse.

[0054] 2. Configuration and Processing of Each Device in pH Sensor Calibration System 100 The configuration and processing of each device included in the pH sensor calibration system 100 shown in Fig. 1 will be described using Fig. 5. Fig. 5 is a block diagram showing an example configuration of each device of the pH sensor calibration system 100 according to the embodiment. Below, an example configuration of the entire pH sensor calibration system 100 according to the embodiment, an example configuration and processing of the calibration device 10, and an example configuration and processing of the pH sensor CS will be described.

[0055] (2-1. Example of the overall configuration of the pH sensor calibration system 100) An example of the overall configuration of the pH sensor calibration system 100 shown in FIG. 1 will be described using FIG. 5. As shown in FIG. 5, the pH sensor calibration system 100 is composed of a calibration device 10 and pH sensors CS (CS-1, CS-2). The calibration device 10 and the pH sensors CS are connected, for example, by serial communication. The calibration device 10 is also connected to various devices (not shown) via a predetermined communication network (not shown) so as to be able to communicate with each other by wire or wirelessly. The predetermined communication network can be any of various communication networks such as the Internet or a dedicated line.

[0056] (2-2. Configuration Example and Processing Example of Calibration Device 10) An example of the configuration and processing of the calibration device 10 will be described with reference to Fig. 5. The calibration device 10 is realized by, for example, a liquid analyzer converter that enables water quality management, plant management, plant control, and water pollution analysis. The calibration device 10 has an input unit 11, a display unit 12, a communication unit 13, a memory unit 14, and a control unit 15.

[0057] (2-2-1. Input section 11) The input unit 11 controls input of various information to the calibration device 10. For example, the input unit 11 is realized by a touch panel or the like, and accepts input of various information to the calibration device 10.

[0058] (2-2-2.Display section 12) The display unit 12 is responsible for displaying various pieces of information from the calibration device 10. For example, the display unit 12 is realized by a display or the like, and displays various pieces of information stored in the calibration device 10.

[0059] (2-2-3. Communications Department 13) The communication unit 13 controls data communication with other devices. For example, the communication unit 13 can execute data communication with a terminal or a higher-level system (not shown) via a router or the like, and can execute various processes described below.

[0060] (2-2-4. Storage section 14) The storage unit 14 stores various pieces of information that the control unit 15 refers to when it operates and various pieces of information that the control unit 15 acquires when it operates. Here, the storage unit 14 can be realized by, for example, a semiconductor memory element such as a random access memory (RAM) or a flash memory, or a storage device 10b that is a non-volatile memory such as a hard disk or an optical disk. Note that, in the example of FIG. 5, the storage unit 14 is installed inside the calibration device 10, but it may be installed outside the calibration device 10, or multiple storage units may be installed.

[0061] (2-2-5. Control unit 15) The control unit 15 controls the entire calibration device 10. The control unit 15 has a first calibration unit 15a-1, a second calibration unit 15a-2, and a calibration management unit 15b. Here, the control unit 15 can be realized by, for example, an electronic circuit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0062] The control unit 15 has a first calibration unit 15a-1 connected to the first pH sensor CS-1. The control unit 15 also has a second calibration unit 15a-2 connected to the second pH sensor CS-2. Similarly, the control unit 15 can have calibration units 15a corresponding to the number of pH sensors CS for which calibration is to be performed in parallel, such as a third calibration unit 15a-3 connected to the third pH sensor CS-3, a fourth calibration unit 15a-4 connected to the fourth pH sensor CS-4, and so on.

[0063] (2-2-5-1. 1st calibration section 15a-1) The first calibration unit 15a-1 calibrates the first pH sensor CS-1, which measures the pH of an aqueous solution. Here, the first pH sensor CS-1 is, for example, a sensor that measures the pH of an aqueous solution using a glass electrode method. For example, the first calibration unit 15a-1 calibrates the first pH sensor CS-1 using one-point calibration. Alternatively, the first calibration unit 15a-1 calibrates the first pH sensor CS-1 using two-point calibration. Alternatively, the first calibration unit 15a-1 calibrates the first pH sensor CS-1 using three-point calibration. The first calibration unit 15a-1 may store the calibration results of the first pH sensor CS-1 in the memory unit 14.

[0064] To explain a specific example, the first calibration unit 15a-1 independently performs pH measurement of the first pH sensor CS-1 immersed in a pH standard solution, and stores the potential difference corresponding to the pH standard solution when the pH becomes stable in the memory unit 14. When calibrating the first pH sensor CS-1, the first calibration unit 15a-1 creates a calibration curve showing the relationship between the potential difference used in the pH measurement of the first pH sensor CS-1 and the pH.

[0065] (2-2-5-2. 2nd calibration section 15a-2) The second calibration unit 15a-2 calibrates a second pH sensor CS-2 that measures the pH of an aqueous solution. Here, the second pH sensor CS-2 is a sensor different from the first pH sensor CS-1. The second pH sensor CS-2 is a sensor that measures the pH of an aqueous solution by, for example, a glass electrode method. For example, the second calibration unit 15a-2 calibrates the second pH sensor CS-2 by one-point calibration. The second calibration unit 15a-2 calibrates the second pH sensor CS-2 by two-point calibration. The second calibration unit 15a-2 calibrates the second pH sensor CS-2 by three-point calibration. The second calibration unit 15a-2 may store the calibration results of the second pH sensor CS-2 in the memory unit 14.

[0066] To explain a specific example, the second calibration unit 15a-2 independently performs pH measurement of the second pH sensor CS-2 immersed in a pH standard solution, and stores the potential difference corresponding to the pH standard solution when the pH becomes stable in the memory unit 14. When calibrating the second pH sensor CS-2, the second calibration unit 15a-2 creates a calibration curve showing the relationship between the potential difference used in the pH measurement of the second pH sensor CS-2 and the pH.

[0067] (2-2-5-3. Calibration Management Department 15b) The calibration management unit 15b manages the calibration of the first pH sensor CS-1 and the second pH sensor CS-2. For example, when the first pH sensor CS-1 and the second pH sensor CS-2 are both immersed in a pH standard solution exhibiting a predetermined pH, the calibration management unit 15b manages the calibration of the first pH sensor CS-1 and the second pH sensor CS-2 so that they can be performed in parallel. Below, specific examples of one-point calibration management processing, two-point calibration management processing, and three-point calibration management processing, as well as pH standard solutions, will be described as calibration management processes performed by the calibration management unit 15b.

[0068] (One-point calibration management process) The calibration management unit 15b executes one-point calibration management processing. For example, the calibration management unit 15b manages one-point calibrations of the first pH sensor CS-1 and the second pH sensor CS-2 so that they can be performed in parallel. At this time, the pH standard solution used for the one-point calibration is one of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity.

[0069] To explain a specific example of the one-point calibration management process, when the aqueous solutions measured by the first pH sensor CS-1 and the second pH sensor CS-2 are in the neutral range (pH 6 to 8), the calibration management unit 15b independently performs pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in a neutral standard solution that exhibits a pH of 6.8 at 25°C. The calibration management unit 15b also stores the potential differences measured when the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the neutral range using the measured potential differences and theoretical values ​​that indicate the relationship between pH and potential difference.

[0070] Furthermore, when the aqueous solutions measured by the first pH sensor CS-1 and the second pH sensor CS-2 are in the acidic range (pH 0 to 6), the calibration management unit 15b independently performs pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in an acidic standard solution that exhibits a pH of 4.0 at 25°C. The calibration management unit 15b also stores the potential differences measured when the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the acidic range using the measured potential differences and theoretical values ​​that indicate the relationship between pH and potential difference.

[0071] Furthermore, when the aqueous solutions measured by the first pH sensor CS-1 and the second pH sensor CS-2 are in the basic range (pH 8 to 14), the calibration management unit 15b independently performs pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in a basic standard solution that exhibits a pH of 10.0 at 25°C. The calibration management unit 15b also stores the potential differences measured when the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the basic range using the measured potential differences and theoretical values ​​showing the relationship between pH and potential difference.

[0072] (2-point calibration management process) The calibration management unit 15b executes two-point calibration management processing. For example, the calibration management unit 15b manages two-point calibrations of the first pH sensor CS-1 and the second pH sensor CS-2 so that they can be performed in parallel. At this time, the pH standard solutions used for the two-point calibration are two of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity.

[0073] To explain a specific example of the two-point calibration management process, when the aqueous solutions measured by the first pH sensor CS-1 and the second pH sensor CS-2 have a pH in the neutral to weakly acidic range (approximately pH 2 to 8), the calibration management unit 15b first performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in a neutral standard solution that exhibits a pH of 6.8 at 25°C, and stores the potential difference obtained when the pH stabilizes in the memory unit 14. Next, the calibration management unit 15b performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in an acidic standard solution that exhibits a pH of 4.0 at 25°C, and stores the potential difference obtained when the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the neutral to weakly acidic range.

[0074] Furthermore, when the aqueous solutions measured by the first pH sensor CS-1 and the second pH sensor CS-2 are in the neutral to weakly basic range (pH 6 to 12), the calibration management unit 15b first performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in, for example, a neutral standard solution showing a pH of 6.8 at 25°C, and stores the potential difference at the time the pH stabilizes in the memory unit 14. Next, the calibration management unit 15b performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in, for example, a basic standard solution showing a pH of 10.0 at 25°C, and stores the potential difference at the time the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the neutral to weakly basic range.

[0075] The calibration management unit 15b can also use pH standard solutions of the same liquid type for the two-point calibration management process. That is, the calibration management unit 15b can perform the two-point calibration management process using, for example, a neutral standard solution of pH 6.8 and a neutral standard solution of pH 7.4. The calibration management unit 15b can also perform the two-point calibration management process using, for example, an acidic standard solution of pH 1.7 and an acidic standard solution of pH 4.0. The calibration management unit 15b can also perform the two-point calibration management process using, for example, a basic standard solution of pH 9.2 and a basic standard solution of pH 10.0.

[0076] (3-point calibration management process) The calibration management unit 15b executes a three-point calibration management process. For example, the calibration management unit 15b manages three-point calibrations of the first pH sensor CS-1 and the second pH sensor CS-2 so that they can be performed in parallel. The pH standard solutions used for the three-point calibration are a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity.

[0077] To explain a specific example of the three-point calibration management process, when the aqueous solution measured by the first pH sensor CS-1 and the second pH sensor CS-2 has a pH ranging over a wide range from weakly basic to weakly acidic (about pH 2 to 12), the calibration management unit 15b first performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in a neutral standard solution that exhibits a pH of 6.8 at 25°C, and stores the potential difference at the time the pH stabilizes in the memory unit 14. Next, the calibration management unit 15b performs independent pH measurements on the first pH sensor CS-1 and the second pH sensor CS-2 immersed in an acidic standard solution that exhibits a pH of 4.0 at 25°C, and stores the potential difference at the time the pH stabilizes in the memory unit 14. Furthermore, the calibration management unit 15b independently measures the pH of the first pH sensor CS-1 and the second pH sensor CS-2 immersed in an acidic standard solution that exhibits a pH of 10.0 at 25°C, and stores the potential difference when the pH stabilizes in the memory unit 14. The calibration management unit 15b then creates calibration curves for the first pH sensor CS-1 and the second pH sensor CS-2 in the weakly basic to weakly acidic range.

[0078] The calibration management unit 15b can also use pH standard solutions of the same liquid property for the three-point calibration management process. That is, the calibration management unit 15b can perform the three-point calibration management process, for example, by using a neutral standard solution of pH 6.8 and a neutral standard solution of pH 7.4 for two of the three points. The calibration management unit 15b can also perform the three-point calibration management process, for example, by using an acidic standard solution of pH 1.7 and an acidic standard solution of pH 4.0 for two of the three points. The calibration management unit 15b can also perform the three-point calibration management process, for example, by using a basic standard solution of pH 9.2 and a basic standard solution of pH 10.0 for two of the three points.

[0079] (Example of pH standard solution) Here, specific examples of pH standard solutions used for calibration are explained. Below, we will explain a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity.

[0080] (neutral standard solution) The neutral standard solution is a neutral phosphate pH standard solution or a phosphate pH standard solution. The neutral standard solution is, for example, a neutral phosphate pH standard solution having a pH of 6.86 at 25°C, which is a buffer solution containing 0.025 mol / kg potassium dihydrogen phosphate and 0.025 mol / kg disodium hydrogen phosphate. Alternatively, the neutral standard solution is, for example, a phosphate pH standard solution having a pH of 7.41 at 25°C, which is a buffer solution containing 0.008695 mol / kg potassium dihydrogen phosphate and 0.03043 mol / kg disodium hydrogen phosphate.

[0081] (acidic standard solution) The acidic standard solution is an oxalate pH standard solution or a phthalate pH standard solution. For example, the acidic standard solution is an oxalate pH standard solution having a pH of 1.68 at 25°C, which is a buffer solution containing 0.05 mol / kg potassium trihydrogen dioxalate. Alternatively, the acidic standard solution is a phthalate pH standard solution having a pH of 4.01 at 25°C, which is a buffer solution containing 0.05 mol / kg potassium hydrogen phthalate.

[0082] (Basic standard solution) The basic standard solution is a borate pH standard solution or a carbonate pH standard solution. The basic standard solution is, for example, a borate pH standard solution having a pH of 9.18 at 25°C, which is a buffer solution containing 0.01 mol / kg sodium borate. The basic standard solution is, for example, a carbonate pH standard solution having a pH of 10.01 at 25°C, which is a buffer solution containing 0.025 mol / kg sodium bicarbonate and 0.025 mol / kg sodium carbonate.

[0083] (2-3. pH sensor CS configuration and processing example) An example of the configuration and processing of the pH sensor CS will be described using Figure 5. The pH sensor CS is realized by a sensor that measures the pH of an aqueous solution using the glass electrode method. For example, the pH sensor CS has a first pH sensor CS-1 and a second pH sensor CS-2.

[0084] (2-3-1. First pH sensor CS-1) The first pH sensor CS-1 is connected to the first calibration unit 15a-1 and is controlled by the first calibration unit 15a-1 via serial communication. At this time, the first pH sensor CS-1 is also connected to the first calibration unit 15a-1 and can directly reference analog values ​​(e.g., voltage values, current values). For example, the first pH sensor CS-1, in response to a command from the first calibration unit 15a-1, detects a potential difference corresponding to the pH of the aqueous solution in which it is immersed and outputs the detected potential difference to the first calibration unit 15a-1.

[0085] (2-3-2. Second pH sensor CS-2) The second pH sensor CS-2 is connected to the second calibration unit 15a-2 and is controlled by the second calibration unit 15a-2 via serial communication. The second pH sensor CS-2 is also connected to the second calibration unit 15a-2 and can directly reference analog values ​​(e.g., voltage values, current values). For example, the second pH sensor CS-2 detects a potential difference corresponding to the pH of the aqueous solution in which it is immersed, in response to a command from the second calibration unit 15a-2, and outputs the detected potential difference to the second calibration unit 15a-2.

[0086] 3. Specific Examples of Processes in the pH Sensor Calibration System 100 A specific example of each process of the pH sensor calibration system 100 according to the embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram showing a specific example of each procedure of the pH sensor calibration system 100 according to the embodiment. A specific example of the calibration procedure will be described below.

[0087] (3-1. Specific example of calibration procedure) A specific example of a calibration procedure for the pH sensor calibration system 100 according to the embodiment will be described. First, as shown in FIG. 6(1), an operator W immerses the pH sensors CS-1 and CS-2 in a first cleaning solution L1, such as pure water, to clean the pH sensors CS-1 and CS-2 (step P11). Next, as shown in FIG. 6(2), the operator W immerses the pH sensors CS-1 and CS-2 in a zero-point buffer solution L2, which is a neutral standard solution (step P12), waits for the zero-point measurements taken by the pH sensors CS-1 and CS-2 to stabilize (step P13), and, once the zero-point measurements have stabilized, operates the calibration device 10 to record the measurements (step P14). Furthermore, as shown in FIG. 6(3), the operator W immerses the pH sensors CS-1 and CS-2 in a second cleaning solution L3, such as pure water, to clean the pH sensors CS-1 and CS-2 (step P15). Then, as shown in Figure 6 (4), the operator W immerses the pH sensors CS-1 and CS-2 in the slope point buffer solution L4, which is an acidic standard solution (step P16), waits for the slope point measurements taken by the pH sensors CS-1 and CS-2 to stabilize (step P17), and once the slope point measurements have stabilized, operates the calibration device 10 to record the measurements (step P18).

[0088] 4. Processing Flow of pH Sensor Calibration System 100 The processing flow of the pH sensor calibration system 100 according to the embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of the processing flow of the pH sensor calibration system 100 according to the embodiment. Note that the processing of steps S101 to S104 below can also be executed in a different order. Furthermore, some of the processing of steps S101 to S104 below may be omitted.

[0089] (4-1. First cleaning process) First, the pH sensor calibration system 100 executes a first cleaning process (step S101). For example, before zero-point calibration, the operator W cleans the pH sensors CS-1 and CS-2 using pure water as the first cleaning liquid L1.

[0090] (4-2. First calibration process) Second, the pH sensor calibration system 100 executes a first calibration process (step S102). For example, the calibration device 10 uses a neutral standard solution with a pH of about 7 as the zero-point buffer solution L2 to calibrate the zero points of the two pH sensors CS-1 and CS-2 in parallel.

[0091] (4-3. Second cleaning process) Third, the pH sensor calibration system 100 executes a second cleaning process (step S103). For example, before the calibration of the slope point, the operator W cleans the pH sensors CS-1 and CS-2 using pure water as the second cleaning liquid L3.

[0092] (4-4. Second calibration process) Fourth, the pH sensor calibration system 100 executes a second calibration process (step S104). For example, the calibration device 10 uses an acidic standard solution with a pH of about 4 as the slope point buffer solution L4 to perform calibrations of the slope points of the pH sensors CS-1 and CS-2 in parallel.

[0093] 5. Effects of the embodiment Finally, the effects of the embodiment will be described below: Effects 1 to 8 corresponding to the processing according to the embodiment will be described below.

[0094] (5-1. Effect 1) First, in the process according to the embodiment described above, the calibration device 10 calibrates the pH sensor CS-1 that measures the pH of an aqueous solution, and also calibrates the pH sensor CS-2 that is different from the pH sensor CS-1. When both the pH sensor CS-1 and the pH sensor CS-2 are immersed in a pH standard solution that exhibits a predetermined pH, the calibration of the pH sensor CS-1 and the pH sensor CS-2 can be performed in parallel. Therefore, this process can shorten the time required to calibrate multiple pH sensors CS.

[0095] (5-2. Effect 2) Second, in the process according to the embodiment described above, the pH standard solution is one of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration device 10 manages the one-point calibrations of the pH sensors CS-1 and CS-2 so that they can be performed in parallel. Therefore, this process can shorten the time required for one-point calibration of multiple pH sensors CS.

[0096] (5-3. Effect 3) Third, in the process according to the embodiment described above, the pH standard solutions are two of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration device 10 manages the two-point calibrations of the pH sensors CS-1 and CS-2 so that they can be performed in parallel. Therefore, this process can shorten the time required for two-point calibration of multiple pH sensors CS.

[0097] (5-4. Effect 4) Fourth, in the process according to the embodiment described above, the pH standard solutions are a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration device 10 manages the three-point calibrations of the pH sensors CS-1 and CS-2 so that they can be performed in parallel. Therefore, this process can shorten the time required for three-point calibration of multiple pH sensors CS.

[0098] (5-5. Effect 5) Fifth, in the process according to the above embodiment, the neutral standard solution is a neutral phosphate pH standard solution or a phosphate pH standard solution, which can shorten the time required to calibrate the multiple pH sensors CS in the neutral range.

[0099] (5-6. Effect 6) Sixth, in the process according to the above embodiment, the acidic standard solution is an oxalate pH standard solution or a phthalate pH standard solution, which can shorten the time required to calibrate the multiple pH sensors CS in the acidic range.

[0100] (5-7. Effect 7) Seventh, in the process according to the above embodiment, the basic standard solution is a borate pH standard solution or a carbonate pH standard solution, which can shorten the time required to calibrate the multiple pH sensors CS in the basic range.

[0101] (5-8. Effect 8) Eighth, in the process according to the embodiment described above, pH sensors CS-1 and CS-2 measure the pH of the aqueous solution by the glass electrode method. Therefore, this process can shorten the time required to calibrate multiple pH sensors CS in a versatile measurement method using glass electrodes.

[0102] 6. Application Examples of the Embodiments Application Examples of the Embodiments are Described below. Application Examples 1 to 4 of the embodiment are described below.

[0103] (6-1. Application Example 1) As a first application example of the embodiment, it is also possible to apply the present invention to the calibration of a dissolved oxygen sensor that measures the amount of dissolved oxygen in an aqueous solution, instead of the pH sensor CS.

[0104] (6-2. Application Example 2) As a second application example of the embodiment, it is also possible to apply the present invention to the calibration of a conductivity sensor that measures the conductivity of an aqueous solution, instead of the pH sensor CS.

[0105] (6-3. Application example 3) As a third application example of the embodiment, it is also possible to apply the present invention to the calibration of an electromagnetic conductivity sensor that measures the electromagnetic conductivity of an aqueous solution, instead of the pH sensor CS.

[0106] (6-4. Application Example 4) As a fourth application example of the embodiment, instead of the pH sensor CS, it can also be applied to the calibration of an oxidation-reduction potential sensor that measures the oxidation-reduction potential of an aqueous solution.

[0107] [7. System] The information including the processing procedures, control procedures, specific names, various data and parameters shown in the above documents and drawings can be changed arbitrarily unless otherwise specified.

[0108] Furthermore, the components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure. In other words, all or part of each device can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0109] Furthermore, all or any part of the processing functions performed by each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware using wired logic.

[0110] [8. Hardware] An example of the hardware configuration of the calibration device 10 will be described. Note that other devices may also have a similar hardware configuration. FIG. 8 is a diagram showing an example of the hardware configuration according to the embodiment. As shown in FIG. 8, the calibration device 10 includes a communication device 10a, a storage device 10b, a memory 10c, and a processor 10d. The components shown in FIG. 8 are connected to each other via a bus or the like.

[0111] The communication device 10a is a transmission line capable of communicating analog signals, a converter capable of superimposing digital signals on the transmission line, a network interface card, etc., and performs communication with other servers. The communication device 10a performs the same function as the communication unit 13 described with reference to FIG. 5 etc. The storage device 10b is a semiconductor memory element such as RAM or flash memory, or a non-volatile memory such as a hard disk or optical disk, and stores programs and databases that operate the functions of each device, such as the calibration device 10 shown in FIG. 5. The storage device 10b performs the same function as the storage unit 14 described with reference to FIG. 5 etc.

[0112] The processor 10d reads out a program that executes the same processing as each processing unit shown in FIG. 5 from the storage device 10b etc. and loads it into the memory 10c, thereby operating a process that executes each function described in FIG. 5 etc. For example, this process executes the same function as each processing unit of the calibration device 10. Specifically, the processor 10d reads out a program having the same function as the first calibration unit 15a-1, the second calibration unit 15a-2, the calibration management unit 15b etc. from the storage device 10b etc. Then, the processor 10d executes a process that executes the same processing as the first calibration unit 15a-1, the second calibration unit 15a-2, the calibration management unit 15b etc.

[0113] In this way, the calibration device 10 operates as a device that executes various processing methods by reading and executing a program. The calibration device 10 can also realize functions similar to those of the above-described embodiment by reading the program from a recording medium using a media reader and executing the read program. Note that the program in these other embodiments is not limited to being executed by the calibration device 10. For example, the present invention can also be applied in the same way to cases where another computer or server executes the program, or where these execute the program in cooperation with each other.

[0114] This program can be distributed via a network such as the Internet. In addition, this program can be recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, a magneto-optical disk (MO), or a digital versatile disk (DVD), and can be executed by being read from the recording medium by a computer.

[0115] [9. Other] Some examples of combinations of the disclosed technical features are set out below.

[0116] (1) A calibration device comprising: a first calibration unit that calibrates a first pH sensor that measures the pH of an aqueous solution; a second calibration unit that calibrates a second pH sensor that is different from the first pH sensor; and a calibration management unit that manages the calibration of the first pH sensor and the second pH sensor so that they can be performed in parallel when both the first pH sensor and the second pH sensor are immersed in a pH standard solution that indicates a predetermined pH.

[0117] (2) The calibration device described in (1), wherein the pH standard solution is one of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration management unit manages one-point calibrations of the first pH sensor and the second pH sensor so that they can be performed in parallel.

[0118] (3) The calibration device described in (1), wherein the pH standard solutions are two of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration management unit manages two-point calibrations of the first pH sensor and the second pH sensor so that they can be performed in parallel.

[0119] (4) The calibration device described in (1) above, wherein the pH standard solutions are a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, and the calibration management unit manages three-point calibrations of the first pH sensor and the second pH sensor so that they can be performed in parallel.

[0120] (5) The calibration device according to any one of (2) to (4), wherein the neutral standard solution is a neutral phosphate pH standard solution or a phosphate pH standard solution.

[0121] (6) The calibration device according to any one of (2) to (5), wherein the acidic standard solution is an oxalate pH standard solution or a phthalate pH standard solution.

[0122] (7) The calibration device according to any one of (2) to (6), wherein the basic standard solution is a borate pH standard solution or a carbonate pH standard solution.

[0123] (8) The calibration device according to any one of (1) to (7), wherein the first pH sensor and the second pH sensor measure the pH of the aqueous solution by a glass electrode method.

[0124] (9) A calibration method in which a computer executes a process to calibrate a first pH sensor that measures the pH of an aqueous solution, calibrate a second pH sensor different from the first pH sensor, and, when the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, manage the calibration of the first pH sensor and the second pH sensor so that they can be executed in parallel.

[0125] (10) A calibration program that causes a computer to execute a process of calibrating a first pH sensor that measures the pH of an aqueous solution, calibrating a second pH sensor that is different from the first pH sensor, and, when the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, managing the calibration of the first pH sensor and the second pH sensor so that they can be executed in parallel. [Explanation of symbols]

[0126] 10 Calibration device 10a Communication equipment 10b Storage device 10c memory 10d processor 11 Input section 12 Display section 13 Communications Department 14 Storage section 15 Control Unit 15a Calibration section 15a-1 1st calibration section 15a-2 2nd calibration section 15b Calibration Management Department 100 pH Sensor Calibration System

Claims

1. a first calibration unit that calibrates a first pH sensor that measures the pH of an aqueous solution; a second calibration unit that calibrates a second pH sensor different from the first pH sensor; a calibration management unit that manages calibrations of the first pH sensor and the second pH sensor so that the calibrations can be performed in parallel when both the first pH sensor and the second pH sensor are immersed in a pH standard solution that exhibits a predetermined pH; A calibration device comprising:

2. The pH standard solution is one of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, The calibration management unit managing one-point calibrations of the first pH sensor and the second pH sensor in parallel; The calibration device of claim 1 .

3. The pH standard solution is two of a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, The calibration management unit managing two-point calibrations of the first pH sensor and the second pH sensor in parallel; The calibration device of claim 1 .

4. The pH standard solutions are a neutral standard solution based on neutrality, an acidic standard solution based on acidity, and a basic standard solution based on basicity, The calibration management unit managing three-point calibrations of the first pH sensor and the second pH sensor in parallel; The calibration device of claim 1 .

5. The neutral standard solution is a neutral phosphate pH standard solution or a phosphate pH standard solution. A calibration device according to any one of claims 2 to 4.

6. The acidic standard solution is an oxalate pH standard solution or a phthalate pH standard solution. A calibration device according to any one of claims 2 to 4.

7. The basic standard solution is a borate pH standard solution or a carbonate pH standard solution. A calibration device according to any one of claims 2 to 4.

8. the first pH sensor and the second pH sensor measure the pH of the aqueous solution by a glass electrode method; A calibration device according to any one of claims 1 to 4.

9. The computer calibrating a first pH sensor that measures the pH of the aqueous solution; calibrating a second pH sensor different from the first pH sensor; When the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, the calibration of the first pH sensor and the calibration of the second pH sensor are managed so as to be executable in parallel. The calibration method to perform the process.

10. On the computer, calibrating a first pH sensor that measures the pH of the aqueous solution; calibrating a second pH sensor different from the first pH sensor; When the first pH sensor and the second pH sensor are both immersed in the same pH standard solution, the calibration of the first pH sensor and the calibration of the second pH sensor are managed so as to be executable in parallel. A calibration program that performs the process.

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