Sensor calibration device, sensor calibration system, sensor calibration method, and sensor calibration program

Abstract

The objective is to provide a sensor calibration device, sensor calibration system, sensor calibration method, and sensor calibration program that can calibrate water quality sensors in water treatment systems at low cost, automatically or autonomously. [Solution] The control device 100, which serves as a sensor calibration device, is equipped with a processor. The processor sends a second treated water source downstream of the first treated water source that the water quality sensor detects to a first water quality sensor 161, which serves as a water quality sensor for detecting the water quality of the treated water of the water treatment system 20. The processor then uses the second treated water source to calibrate the water quality sensor.

Description

Technical Field

[0001] The present disclosure relates to a sensor calibration device, a sensor calibration system, a sensor calibration method, and a sensor calibration program.

Background Art

[0002] Patent Document 1 discloses a zero calibration method capable of reliably performing zero calibration in a water quality measurement device that generates zero calibration water using a filter or the like. This zero calibration method provides a zero calibration water generation path in parallel with the water flow path during normal measurement that connects the detection water source and the detection unit (measurement cell), inserts a zero water generation filter and a three-way valve into the zero calibration water generation path, and oppositely arranges a light emitting element and a light receiving element for detecting transmitted light at a position sandwiching a drainage path that connects the three-way valve and a drainage tank. When the difference between the light reception amount when zero water is first passed through the zero calibration water generation path and the drainage path and the light reception amount during normal water flow becomes small, it is set as the zero calibration value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, it is premised on generating zero calibration water, and there are problems in terms of cost increase due to adopting a configuration for generating zero calibration water for zero calibration. For example, in a water treatment system capable of treating wastewater such as domestic wastewater, when the water quality of the water to be treated is poor and the water quality sensor gets dirty in a short period, it has been difficult to detect the water quality of the water without calibrating the water quality sensor. In particular, in a small-scale decentralized water treatment system installed for each facility, it is desired to be able to complete calibration of the water quality sensor at a low cost without having to go to the installation location of the water treatment system.

[0005] This disclosure aims to provide a sensor calibration device, a sensor calibration system, a sensor calibration method, and a sensor calibration program that can calibrate water quality sensors in water treatment systems at low cost, automatically or autonomously. [Means for solving the problem]

[0006] The sensor calibration device according to the first embodiment includes a processor, which sends a second treated water downstream of the first treated water that the water quality sensor is targeting to detect to a water quality sensor that detects the water quality of treated water in a water treatment system, and calibrates the water quality sensor using the sent second treated water.

[0007] In the sensor calibration apparatus according to the second embodiment, the processor sends the second treated water to the water quality sensor when the water quality of the second treated water is equal to or greater than a predetermined threshold that represents water quality suitable for calibration of the water quality sensor.

[0008] The sensor calibration device according to the third embodiment is a sensor calibration device according to the first embodiment or the second embodiment, wherein the first treated water is the inflow water at the inflow stage, and the second treated water is the treated water.

[0009] The sensor calibration device according to the fourth embodiment is a sensor calibration device according to any one of the first to third embodiments, wherein the water treatment system includes a plurality of treatment stages related to water treatment, the first treated water is treated water from a predetermined treatment stage related to water treatment, and the second treated water is treated water from a treatment stage downstream of the predetermined treatment stage.

[0010] The sensor calibration device according to the fifth embodiment is a sensor calibration device according to any one of the first to fourth embodiments, wherein the water quality sensor is an optical sensor.

[0011] The sensor calibration system according to the sixth embodiment comprises a first water quality sensor for detecting the water quality of the first treated water, and a sensor calibration device according to any one of the first to fifth embodiments.

[0012] The sensor calibration system according to the seventh embodiment includes a second water quality sensor for detecting the water quality of the second treated water, in addition to the sensor calibration system according to the sixth embodiment.

[0013] The sensor calibration method according to the eighth aspect involves a computer performing a process to calibrate a water quality sensor that detects the water quality of treated water in a water treatment system. This process involves sending a second treated water source downstream of the first treated water source that the water quality sensor is targeting, and using the second treated water source that is sent to the water quality sensor.

[0014] The sensor calibration program according to the ninth embodiment causes a computer to perform a process in which it sends a second treated water downstream of the first treated water that the water quality sensor is targeting to detect, to a water quality sensor that detects the water quality of treated water in a water treatment system, and then calibrates the water quality sensor using the sent second treated water. [Effects of the Invention]

[0015] According to the disclosed technology, water quality sensors in water treatment systems can be calibrated inexpensively, automatically, or autonomously. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows the schematic configuration of the sensor calibration system of this embodiment. [Figure 2] This block diagram shows a schematic configuration of the water treatment system according to this embodiment. [Figure 3] This is a block diagram showing an example of the hardware configuration of the control device according to this embodiment. [Figure 4] A block diagram showing an example of the functional configuration of the control device according to this embodiment. [Figure 5] This flowchart shows an example of the calibration process according to this embodiment. [Figure 6] It is a graph showing an example of the determination criteria based on the water quality score according to this embodiment.

Mode for Carrying Out the Invention

[0017] Hereinafter, the sensor calibration system 10 according to this embodiment will be described with reference to the drawings. In each drawing, the same or equivalent components and parts are given the same reference numerals. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios. Further, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present disclosure.

[0018] <Overview of this Embodiment> Generally, it is considered difficult to measure the water quality of the influent water flowing into the water treatment system using a water quality sensor. This is partly because the water quality sensor gets very dirty very quickly due to the dirty influent water, and basically, it was difficult to correctly measure the water quality of the influent water without cleaning the water quality sensor immediately before measuring the water quality of the influent water and then calibrating it. Another reason is the deterioration of the water quality sensor over time. Note that "deterioration" is a term that includes, for example, deterioration due to dirt, scratches, wear, as well as deterioration over time and deterioration due to use. For example, the deterioration in the case of an optical sensor includes a decrease in the light emission intensity of the light source in the light emitting part and dirt on the surface of the light receiving part.

[0019] Therefore, the sensor calibration system 10 of this embodiment returns the treated water downstream of the water treatment system to the upstream of the water treatment system, and calibrates the water quality sensor arranged upstream of the water treatment system using the treated water. The calibration of the water quality sensor is performed, for example, by updating the reference signal intensity. Note that the treated water in this embodiment includes the influent water flowing into the water treatment system, the water in the treatment process in the water treatment system, and the water treated by the water treatment system.

[0020] For example, when the water quality sensor is an optical sensor, the water quality of the water to be measured is calculated based on the absorbance. The absorbance of the water to be measured is calculated, for example, using the following formula (1).

[0021]

Number

[0022] Hereinafter, when explaining the variables in the formula, “_” is used. For example, “A_sample” represents the left side of the above formula (1), and it means that what comes after “_” is a subscript. In formula (1), “I_dark” is the signal intensity in the state where light is blocked. “I_sample” is the signal intensity of the water to be measured. “I_2” is the signal intensity of the reference water. The calibration of the water quality sensor is performed, for example, by updating “I_2” using the signal intensity of the treated water downstream of the water treatment system. Therefore, according to the sensor calibration system 10 of the present embodiment, by relatively calibrating the upstream water quality sensor with the treated water downstream of the water treatment system as a reference, the influence due to the deterioration of the water quality sensor can be suppressed.

[0023] FIG. 1 is a diagram showing a schematic configuration of the sensor calibration system 10 of the present embodiment. As shown in FIG. 1, the sensor calibration system 10 includes a water treatment system 20, a first water quality sensor 161, and a second water quality sensor 162.

[0024] The water treatment system 20 is a system that autonomously performs water treatment on influent water. In this embodiment, the water treatment system 20 purifies and recycles domestic wastewater, including human waste, and other miscellaneous domestic wastewater, making it reusable. The water treatment system 20 is, for example, a small to medium-scale decentralized water treatment device installed in evacuation shelters, etc. Alternatively, the water treatment system 20 may be a large-scale water treatment system installed in a wastewater treatment facility. The water treatment system 20 may be a water treatment system with a single treatment, or it may be a water treatment system that includes multiple treatment stages. The multiple treatment stages may include, for example, biological treatment, electrolysis, filtration, and chlorine treatment.

[0025] Furthermore, the first water quality sensor 161 measures the water quality of the influent. The second water quality sensor 162 measures the water quality of the treated water. Hereafter, when it is not necessary to distinguish between the first water quality sensor 161 and the second water quality sensor 162, they will be collectively referred to as the "water quality sensor." Examples of water quality sensors include optical sensors, EC sensors, pH sensors, turbidity sensors, chromaticity sensors, SS (suspended solids) sensors, ORP (oxidation-reduction potential) sensors, residual chlorine meters, and DO (dissolved oxygen) sensors. Note that any water quality sensor that can be calibrated using treated water may be used. Also, the water quality sensor may consist of multiple sensors.

[0026] In this embodiment, we will describe a case in which a first water quality sensor 161, which measures the water quality of the influent water, is calibrated using treated water in a water treatment system 20 that includes multiple treatment stages. In the following description, treated water before passing through the RO (Reverse Osmosis membrane) filter will be simply referred to as "treated water," and treated water after passing through the RO filter will also be referred to as "final treated water." Influent water is an example of "first treated water." Final treated water is an example of "second treated water" and "treated water."

[0027] (Overall structure) Figure 2 is a block diagram illustrating the schematic configuration of the water treatment system 20 according to this embodiment. As shown in Figure 2, the sensor calibration system 10 of this embodiment is incorporated into the water treatment system 20, so the water treatment system 20 will be described. The water treatment system 20 of this embodiment includes an inlet tank 21, a conditioning tank 22, a biological treatment tank 23, an electrolysis tank 24, an intermediate tank 25, an RO filter 26, and a storage tank 27. The water treatment system 20 also includes a control device 100, a first water quality sensor 161, a second water quality sensor 162, and a pump 163. The inlet tank 21, conditioning tank 22, biological treatment tank 23, electrolysis tank 24, intermediate tank 25, RO filter 26, and storage tank 27 are connected by a water flow path driven by a pump (not shown). Note that Figure 2 is a diagram illustrating the water treatment system 20 of this embodiment, and the arrangement and configuration of various components such as tanks, sensors, filters, pumps, and flow paths are not limited to Figure 2. In other words, not all components of a water treatment system, such as tanks, sensors, filters, pumps, and flow paths, are essential. They can be appropriately selected, combined, and configured depending on the water quality of the water to be treated. The arrows shown in Figure 2 indicate the direction of water flow. In this embodiment, the inflow tank 21 is considered the "upstream" side, and the storage tank 27 is considered the "downstream" side. The control device 100 is an example of a "sensor calibration device".

[0028] The inflow tank 21 is a tank for temporarily storing inflow water that flows in from the outside.

[0029] The adjustment tank 22 is a tank that homogenizes variations in the volume and quality of treated water flowing in from the inflow tank 21, and stabilizes the load on the biological treatment tank 23, which will be described later.

[0030] The biological treatment tank 23 is a tank that uses microorganisms to decompose organic matter and other substances in the treated water. In the biological treatment tank 23, for example, organic pollutants and other substances in the treated water are decomposed by the activity of the microbial community.

[0031] The electrolysis tank 24 is a tank that performs electrolysis treatment on the treated water. In the electrolysis tank 24, for example, nitrogen and other substances are removed from the treated water by electrolysis.

[0032] The intermediate tank 25 is a tank that temporarily stores treated water from the electrolysis tank 24. The intermediate tank 25 regulates the supply amount to the RO filter 26.

[0033] RO filter 26 is a filter that uses an RO membrane to remove dissolved components, fine particles, and microorganisms from water, thereby producing highly purified treated water.

[0034] The storage tank 27 is a tank for storing the final treated water that has passed through the RO filter 26.

[0035] The control device 100 controls the water volume, water pressure, circulation speed, and circulation interval of the water circulating within the water treatment system 20, as well as the circulation path and water treatment in each tank. The control device 100 also receives signals from the water quality sensor and controls the operation of the pump.

[0036] The first water quality sensor 161 is installed in the inflow tank 21 or the channel through which the inflow water flows, and measures the water quality of the inflow water. The second water quality sensor 162 is installed in the storage tank 27 or the channel through which the final treated water flows, and measures the water quality of the final treated water.

[0037] Pump 163 is a pump that sends the final treated water to the first water quality sensor 161. Specifically, when pump 163 is driven, the final treated water from the storage tank 27 is sent to the inflow tank 21.

[0038] (Hardware configuration) Figure 3 is a block diagram showing an example of the hardware configuration of the control device 100 according to this embodiment. The control device 100 in this embodiment is composed of a CPU (Central Processing Unit) 110, ROM (Read Only Memory) 120, RAM (Random Access Memory) 130, storage 140, communication I / F 150, and input / output I / F 160. Each component is connected to the others so as to be able to communicate with each other via a bus 170.

[0039] The CPU 110 is a central processing unit that executes various programs and controls various parts. The ROM 120 stores various programs and data. In this embodiment, the ROM 120 stores data including the calibration program 121. The calibration program 121 may also be stored in the storage 140, which will be described later. The RAM 130 temporarily stores programs or data as a working area. That is, the CPU 110 reads a program from the ROM 120 or storage 140 and executes the program using the RAM 130 as a working area.

[0040] The calibration program 121 is a program that performs various processes, including those described later. When the calibration program 121 is executed, the control device 100 uses various hardware resources to perform processes based on the calibration program 121.

[0041] Storage 140 consists of flash memory, SSD (Solid State Drive), etc., and stores various programs and data.

[0042] The communication interface 150 is an interface for communicating with other devices. Specifically, the communication interface 150 communicates with various devices, such as a central server (not shown), that manages the water treatment system 20, via a network.

[0043] The input / output interface 160 is an interface for connecting to input / output devices and is used for inputting and outputting various types of information. In this embodiment, the input / output interface 160 is connected to the first water quality sensor 161, the second water quality sensor 162, and the pump 163, etc. The control device 100 is connected to the first water quality sensor 161, the second water quality sensor 162, and the pump 163, etc. via the input / output interface 160 to measure the water quality of the treated water, control the drive of the pump, and calibrate the water quality sensors, etc.

[0044] (Functional Configuration) Figure 4 is a block diagram showing an example of the functional configuration of the control device 100 according to this embodiment. As shown in Figure 4, in this embodiment, the control device 100 functions as a detection unit 111, a measurement unit 112, a transmission unit 113, and a calibration unit 114 when the CPU 110 executes the calibration program 121.

[0045] The detection unit 111 has the function of detecting the inflow of treated water. Specifically, the detection unit 111 monitors the flow, volume, and drainage status of the discharged treated water, and detects whether or not treated water is flowing into each tank.

[0046] The measurement unit 112 has the function of measuring the water quality of the treated water. Specifically, the measurement unit 112 measures the turbidity, color, viscosity, absorbance, electrical conductivity, and residual chlorine concentration of the treated water and calculates the water quality score of the treated water.

[0047] The discharge unit 113 has the function of dispensing treated water by controlling the drive of the pump. Specifically, the discharge unit 113 discharges the downstream treated water to a water quality sensor installed upstream of the treated water.

[0048] Furthermore, the discharge unit 113 may be configured to discharge at least a portion of the treated water, whose water quality score measured by the measurement unit 112 is equal to or greater than a predetermined threshold, to the water quality sensor. The predetermined threshold is, for example, a water quality score that indicates water quality suitable for calibration of the water quality sensor. The predetermined threshold may be set appropriately depending on the type of water quality sensor to be calibrated, the treatment stage in which the water quality sensor to be calibrated is installed, and the treatment stage of the discharged treated water.

[0049] The calibration unit 114 has the function of calibrating the water quality sensor. Specifically, the calibration unit 114 calibrates the water quality sensor using treated water delivered by the delivery unit 113. As an example, the calibration unit 114 calibrates the water quality sensor by performing zero-point calibration using treated water. In addition, if an optical sensor is used as the water quality sensor, the calibration unit 114 calibrates the water quality sensor by updating the reference signal intensity of the optical sensor.

[0050] Next, the operation of the sensor calibration system 10 according to this embodiment will be described.

[0051] (Calibration process) Figure 5 is a flowchart showing an example of the calibration process according to this embodiment. The control device 100 calibrates the first water quality sensor 161 by performing the calibration process. In this embodiment, the calibration process is performed by the CPU 110 of the control device 100 reading the calibration program 121 from the ROM 120 or storage 140, loading it into the RAM 130, and executing it. The calibration process is, for example, a process that is repeatedly performed each time treated water is stored in the storage tank 27 while the water treatment system 20 is in operation.

[0052] In step S100 of Figure 5, the CPU 110 detects that treated water has flowed in. Specifically, the CPU 110 detects that treated water has flowed from the upstream tank to the downstream tank of the water treatment system 20. For example, the CPU 110 detects that the final treated water has flowed into the storage tank 27.

[0053] In step S101, the CPU 110 measures the water quality of the treated water using a second water quality sensor 162 located downstream of the water treatment system 20. Specifically, the CPU 110 obtains a water quality score for the treated water using the second water quality sensor 162. The water quality score is an index value calculated from the turbidity, absorbance, color, electrical conductivity, and residual chlorine concentration of the treated water. As an example, the CPU 110 calculates the water quality score based on the absorbance of the treated water measured using an optical sensor.

[0054] In step S102, the CPU 110 determines whether the water quality of the treated water is above a predetermined threshold. Specifically, the CPU 110 determines whether the water quality score of the treated water measured in step S101 is above a set value that is suitable for calibrating the water quality sensor. If the CPU 110 determines that the water quality of the treated water is above the predetermined threshold (step S102: YES), it proceeds to step S104. On the other hand, if the CPU 110 determines that the water quality score is not above the predetermined threshold (step S102: NO), it proceeds to step S103.

[0055] Figure 6 is a graph showing an example of the criteria for judgment based on water quality scores according to this embodiment. Graph G shown in Figure 6 is, as an example, a graph showing the water quality score for each batch of final treated water in the water treatment system 20. The water quality score in this embodiment is, as an example, shown as a normalized value between 0 and 1 based on absorbance. Graph G is a graph with the water quality score on the vertical axis and the batch number assigned to each batch of water treatment on the horizontal axis. Plots P1, shown as black circles, indicate a water quality score below a predetermined threshold. Plots P2, shown as white circles, indicate a water quality score above a predetermined threshold. The dashed line L1 indicates the predetermined threshold. The dashed line L2 indicates the minimum water quality score required for final treated water. In other words, in Figure 6, as an example, it is shown that for treatment numbers 1 to 3, the water quality score was determined to be below the predetermined threshold. It is also shown that for treatment number 4, the water quality score was determined to be above the predetermined threshold. The same applies to treatment numbers 5 and beyond, so a detailed explanation is omitted.

[0056] In step S103 of Figure 5, the CPU 110 waits until the next inflow of treated water. For example, the CPU 110 waits until treated water flows into the storage tank 27. Then, the CPU 110 returns to step S100.

[0057] In step S104, the CPU 110 sends treated water to the first water quality sensor 161 upstream of the water treatment system 20. Specifically, the CPU 110 sends the treated water whose water quality was measured in step S101 to the upstream tank. For example, the CPU 110 drives the pump 163 to send at least a portion of the final treated water stored in the storage tank 27 to the inflow tank 21.

[0058] In step S105, the CPU 110 calibrates the first water quality sensor 161 using the treated water. Specifically, the CPU 110 calibrates the first water quality sensor 161 using the treated water delivered in step S104. Then, the CPU 110 completes the calibration process.

[0059] (Summary of this embodiment) In this embodiment, the control device 100 drives a pump 163 to send the final treated water stored in the storage tank 27 downstream of the inflow water of the inflow tank 21, which is the target of detection by the first water quality sensor 161, to the first water quality sensor 161 that detects the water quality of the treated water of the water treatment system 20. The first water quality sensor 161 is then calibrated using the sent final treated water. Therefore, according to the control device 100 of this embodiment, the water quality sensor in the water treatment system can be calibrated at low cost and automatically or autonomously. Furthermore, according to the control device 100 of this embodiment, since the water quality sensor that detects the inflow water is calibrated using the final treated water processed downstream, the water quality sensor can be calibrated at low cost and stably without generating or preparing zero calibration water.

[0060] In this embodiment, the control device 100 measures the water quality of the final treated water in the storage tank 27 using the second water quality sensor 162 to calculate a water quality score. If the water quality score is above a predetermined threshold, it drives the pump 163 to send the final treated water to the first water quality sensor 161. Therefore, according to the control device 100 of this embodiment, the water quality sensor can be calibrated using treated water with a water quality score above a predetermined threshold, thus maintaining the calibration quality of the water quality sensor.

[0061] [Other embodiments] The sensor calibration system 10 of this embodiment included a first water quality sensor 161 and a second water quality sensor 162. However, it is not limited to this, and the sensor calibration system 10 of this embodiment may include only the first water quality sensor 161. That is, the sensor calibration system 10 of this embodiment may perform calibration of the water quality sensor by sending the treated water to the upstream water quality sensor regardless of the water quality of the treated water downstream. For example, when the final treated water is stored in the storage tank 27, the sensor calibration system 10 sends the final treated water to the inflow tank 21 at a predetermined timing (for example, every predetermined period). Therefore, according to the sensor calibration system 10 of this embodiment, the water quality sensor can be calibrated periodically by performing calibration regardless of the water quality of the treated water.

[0062] In this embodiment, the control device 100 calibrated the first water quality sensor 161 using the final treated water. However, the device is not limited to this, and the treatment stage of the treated water used for calibration and the installation location of the sensor to be calibrated are not limited. The treated water used for calibration may be treated water from any of the treatment stages of the adjustment tank 22, biological treatment tank 23, electrolysis tank 24, intermediate tank 25, and storage tank 27. The sensor to be calibrated may be a sensor installed in any of the inflow tank 21, adjustment tank 22, biological treatment tank 23, electrolysis tank 24, and intermediate tank 25, or in a flow path, etc. The treatment stage of the treated water used for calibration is not limited to the treatment stages described above, but may be any treatment stage. The installation location of the sensor to be calibrated is not limited to the locations described above, but may be any location. For example, the sensor to be calibrated may be a water quality sensor that detects the water quality of concentrated wastewater. Therefore, according to the control device 100 of this embodiment, the water quality sensor can be calibrated according to the configuration of the water treatment system and the operating conditions, etc. Furthermore, according to the control device 100 of this embodiment, for example, if the treated water used for calibration is treated water upstream of the RO filter 26, the processing load on the RO membrane used in the RO filter 26 can be reduced.

[0063] In this embodiment, the control device 100 detects the inflow of treated water and calibrates the first water quality sensor 161 if the water quality of the treated water is above a predetermined threshold. However, the conditions for calibrating the first water quality sensor 161 are not limited to this. The control device 100 in this embodiment may calibrate the first water quality sensor 161 when predetermined conditions are met. These predetermined conditions include, for example, when a decrease in the signal intensity of the first water quality sensor 161 is detected, when the number of calibrations of the water quality sensor in a predetermined period (e.g., one day) falls below a predetermined number, and when the cumulative value of pollution in the inflow water exceeds a predetermined threshold. Furthermore, the control device 100 may set the conditions for calibrating the first water quality sensor 161 by combining multiple conditions. Therefore, according to the control device 100 in this embodiment, the water quality sensor can be calibrated at an appropriate timing.

[0064] In this embodiment, the control device 100 performed calibration of the first water quality sensor 161 using treated water discharged from the storage tank 27. The control device 100 in this embodiment may perform cleaning of the first water quality sensor 161 before calibration. For example, the control device 100 cleans the first water quality sensor 161 by flowing treated water discharged from the storage tank 27 over the first water quality sensor 161. Therefore, the control device 100 in this embodiment can suppress the effects of deterioration due to fouling of the water quality sensor.

[0065] Furthermore, the control device 100 of this embodiment may determine whether to calibrate the first water quality sensor 161 or wash the first water quality sensor 161 based on the water quality score of the treated water measured by the second water quality sensor 162. Specifically, if the water quality score of the treated water is above a predetermined threshold, the control device 100 will calibrate the first water quality sensor 161 using the treated water. If the water quality score of the treated water is below a predetermined threshold, the control device 100 will wash the first water quality sensor 161 using the treated water. Note that if the water quality score of the treated water is below a minimum water quality score, the control device 100 may choose not to calibrate or wash the first water quality sensor 161. Also, if the water quality score of the treated water is below a predetermined threshold, the control device 100 may choose to pre-wash (i.e., perform preliminary washing) the first water quality sensor 161 using the treated water. Furthermore, if the water quality score of the treated water is above a predetermined threshold, the control device 100 may use the treated water to wash the first water quality sensor 161 and then calibrate the first water quality sensor 161. Therefore, according to the control device 100 of this embodiment, the effects of deterioration of the water quality sensor can be suppressed.

[0066] Furthermore, the configurations of the sensor calibration system 10, water treatment system 20, and control device 100 described in the above embodiment are examples and may be modified as needed without departing from the main purpose.

[0067] Furthermore, the program processing flow described in the above embodiment is just one example, and unnecessary steps may be deleted, new steps added, or the processing order rearranged, as long as it does not deviate from the main purpose.

[0068] Furthermore, in the above embodiment, each process that the CPU reads and executes the software (program) may be executed by various processors other than the CPU. Examples of processors in this case include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacturing, and dedicated electrical circuits such as ASICs (Application Specific Integrated Circuits) which have a circuit configuration specifically designed to execute a particular process.

[0069] Furthermore, the operation of the processor in the above embodiment may not be performed by a single processor, but may be performed by multiple processors located in physically separate locations working together. Also, the order of the processor operations is not limited to the order described in the above embodiment, but may be changed as appropriate.

[0070] Furthermore, although the above embodiment describes a configuration in which the information processing program is pre-stored (installed) in ROM, the invention is not limited to this. The program may be provided in the form of a recording medium such as a CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory), and USB (Universal Serial Bus) memory. Alternatively, the program may be provided in the form of a download from an external device via a network. This disclosure is also applicable to programs and program products. [Explanation of Symbols]

[0071] 10 Sensor Calibration System 20 Water Treatment Systems 21 Inflow tank 22 Adjustment tank 23. Biological treatment tank 24 Electrolysis chamber 25 Intermediate tank 26 RO filter 27 Storage tank 100 Control device (sensor calibration device) 110 CPU (Processor) 111 Detection unit 112 Measurement Unit 113 Dispatch Unit 114 Calibration Department 121 Calibration Program 161 First Water Quality Sensor 162 Second water quality sensor 163 Pump

Claims

1. Equipped with a processor, The aforementioned processor, To the first water quality sensor that detects the water quality of the first treated water in a water treatment system, the second treated water, which is downstream of the first treated water targeted by the first water quality sensor, is supplied. The first water quality sensor is calibrated using the second treated water that has been discharged. The aforementioned processor, The water quality of the second treated water is obtained, calculated based on the measurement results of the second water quality sensor that detects the water quality of the second treated water. When the water quality of the second treated water is above a predetermined threshold that represents water quality suitable for calibration of the first water quality sensor, the second treated water is sent to the first water quality sensor. Sensor calibration device.

2. The aforementioned first treated water is the inflow water at the inflow stage, The aforementioned second treated water is treated water that has already been treated. The sensor calibration apparatus according to claim 1.

3. The water treatment system includes multiple treatment stages related to water treatment, The aforementioned first treated water is treated water from a predetermined treatment stage related to water treatment, The second treated water is treated water from a treatment stage downstream of the predetermined treatment stage. The sensor calibration apparatus according to claim 1.

4. The first water quality sensor and the second water quality sensor are optical sensors. The sensor calibration apparatus according to claim 1.

5. A first water quality sensor for detecting the water quality of the first treated water, A sensor calibration device according to any one of claims 1 to 4, Equipped with, Sensor calibration system.

6. The system includes a second water quality sensor for detecting the water quality of the second treated water, The sensor calibration system according to claim 5.

7. To the first water quality sensor that detects the water quality of the first treated water in a water treatment system, the second treated water, which is downstream of the first treated water targeted by the first water quality sensor, is supplied. The first water quality sensor is calibrated using the second treated water that has been discharged. The water quality of the second treated water is obtained, calculated based on the measurement results of the second water quality sensor that detects the water quality of the second treated water. When the water quality of the second treated water is above a predetermined threshold that represents water quality suitable for calibration of the first water quality sensor, the second treated water is sent to the first water quality sensor. A sensor calibration method in which a computer performs the processing.

8. To the first water quality sensor that detects the water quality of the first treated water in a water treatment system, the second treated water, which is downstream of the first treated water targeted by the first water quality sensor, is supplied. The first water quality sensor is calibrated using the second treated water that has been discharged. The water quality of the second treated water is obtained, calculated based on the measurement results of the second water quality sensor that detects the water quality of the second treated water. When the water quality of the second treated water is above a predetermined threshold that represents water quality suitable for calibration of the first water quality sensor, the second treated water is sent to the first water quality sensor. A sensor calibration program to allow a computer to perform a process.

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