Dissolved oxygen sensor calibration system and calibration method thereof

Abstract

The invention provides a dissolved oxygen sensor calibration system and a calibration method thereof. The dissolved oxygen sensor calibration system comprises a thermostatic bath device, a dissolved oxygen adjusting device, a sensor to be calibrated, a reference dissolved oxygen sensor and a controller, the controller can traverse the reference dissolved oxygen information and the to-be-detected dissolved oxygen information when the dissolved oxygen medium is in all the preset dissolved oxygen amounts, and calibrate the to-be-calibrated sensor based on the reference dissolved oxygen information and the to-be-detected dissolved oxygen information when the multiple groups of the preset dissolved oxygen amounts are in time. The controller is used for controlling the dissolved oxygen amount of the dissolved oxygen medium to reach each preset dissolved oxygen amount, automatic adjustment, automatic detection and automatic calibration are achieved, rapid and accurate calibration of the dissolved oxygen sensor is achieved, the calibration efficiency and reliability are effectively improved, the method is suitable for oxygen sensor calibration work in various application scenes, and the application prospect is wide. The device has the advantages of remarkable application value and popularization prospect, simple structure, good stability and reliability and the like.

Description

Technical Field

[0001] This invention relates to the field of sensor calibration technology, and in particular to a dissolved oxygen sensor calibration system and calibration method thereof. Background Technology

[0002] Currently, dissolved oxygen calibration on the market generally uses two-point calibration: zero-point calibration (oxygen-free) and saturated oxygen calibration.

[0003] The method for preparing oxygen-free water used in zero-point calibration is to add sodium sulfite (Na2SO3) and trace amounts of cobalt chloride (CoCl2) to distilled water. CoCl2 acts as a catalyst, while Na2SO3 acts as a reducing agent to react with oxygen molecules in the water. The chemical reagent Na2SO3 is irritating to the eyes, skin, and mucous membranes, and also causes some environmental pollution.

[0004] The method for preparing saturated oxygen for saturated oxygen calibration is to continuously inject air into a container filled with tap water using an air pump for at least 60 minutes, and finally let the resulting aqueous solution stand for 30 minutes. This process takes less time than the principal's.

[0005] Therefore, it is necessary to provide a method that can quickly and accurately calibrate without the use of chemical reagents, thereby eliminating the hazards to personnel and the pollution to the environment, and effectively solving the above problems. Summary of the Invention

[0006] This invention provides a dissolved oxygen sensor calibration system and calibration method that can be calibrated quickly and accurately.

[0007] This invention provides a dissolved oxygen sensor calibration system, comprising the following components:

[0008] Thermostatic bath device, capable of storing dissolved oxygen medium;

[0009] A dissolved oxygen regulating device, connected to the constant temperature bath, is capable of adjusting the dissolved oxygen content of the dissolved oxygen medium.

[0010] The sensor to be calibrated is installed in the constant temperature bath device and is capable of detecting the dissolved oxygen information of the dissolved oxygen medium.

[0011] A reference dissolved oxygen sensor, installed in the constant temperature bath, is capable of detecting the reference dissolved oxygen information of the dissolved oxygen medium.

[0012] The controller is connected to the dissolved oxygen regulating device, the sensor to be calibrated, and the reference dissolved oxygen sensor. It can control the dissolved oxygen regulating device to adjust the oxygen content of the dissolved oxygen medium in the constant temperature bath. It can traverse the reference dissolved oxygen information and the dissolved oxygen information to be measured when the dissolved oxygen medium is at all preset dissolved oxygen levels. The same pair of reference dissolved oxygen information and the dissolved oxygen information to be measured is used as a group of detection information. The sensor to be calibrated is calibrated based on multiple groups of detection information.

[0013] Optionally, the dissolved oxygen regulating device includes the following components:

[0014] The oxygen reduction component can increase the dissolved oxygen content of the dissolved oxygen medium by reducing the oxygen content through nitrogen gas.

[0015] An oxygenation component is used to increase the dissolved oxygen content of the dissolved oxygen medium.

[0016] Both the oxygen-reducing component and the oxygen-enhancing component are installed in the constant temperature bath device.

[0017] Optionally, the plurality of preset dissolved oxygen amounts include dissolved oxygen amounts when the dissolved oxygen medium is in a zero-oxygen state and dissolved oxygen amounts when the dissolved oxygen medium is in a saturated oxygen state.

[0018] Optionally, the constant temperature bath device can also adjust the temperature of the dissolved oxygen medium to reach multiple preset dissolved oxygen medium temperatures;

[0019] The controller can traverse the baseline dissolved oxygen information and the dissolved oxygen information to be measured at all preset temperatures and all preset dissolved oxygen levels.

[0020] Each of the aforementioned detection information groups includes dissolved oxygen medium temperature information, baseline dissolved oxygen information, and dissolved oxygen information to be measured.

[0021] Optionally, the constant temperature bath device is also equipped with a sealing device, which can control the constant temperature bath device to be sealed or open.

[0022] The constant temperature bath device is also equipped with a pressure sensor connected to the controller.

[0023] The present invention also provides a calibration method based on the above-described dissolved oxygen sensor calibration system, comprising the following steps;

[0024] S1, multiple preset dissolved oxygen amounts for preset dissolved oxygen media;

[0025] S2. Adjust the dissolved oxygen content of the dissolved oxygen medium, traverse the baseline dissolved oxygen information and the dissolved oxygen information to be tested when the dissolved oxygen medium is at all preset dissolved oxygen content, and take the same pair of baseline dissolved oxygen information and the dissolved oxygen information to be tested as a group of detection information.

[0026] S3. The sensor to be calibrated is calibrated based on multiple sets of detection information.

[0027] Optionally, step S2 includes:

[0028] The controller controls the dissolved oxygen regulating device to introduce nitrogen into the dissolved oxygen medium until the reference dissolved oxygen sensor detects that the oxygen content of the dissolved oxygen medium has reached the preset dissolved oxygen content with the lowest dissolved oxygen content.

[0029] The controller periodically controls the dissolved oxygen regulating device to increase the dissolved oxygen content of the dissolved oxygen medium. When the dissolved oxygen content in the dissolved oxygen medium is at a preset dissolved oxygen content, the reference dissolved oxygen information detected by the reference dissolved oxygen sensor is obtained, and the sensor to be calibrated detects the dissolved oxygen information to be measured.

[0030] The same pair of baseline dissolved oxygen information and the dissolved oxygen information to be measured are treated as a group of detection information.

[0031] Optionally, obtaining the reference dissolved oxygen information detected by the reference dissolved oxygen sensor and the dissolved oxygen information to be measured detected by the sensor to be calibrated includes:

[0032] The reference dissolved oxygen sensor detects multiple raw reference dissolved oxygen information, while the sensor to be calibrated detects multiple raw dissolved oxygen information to be measured.

[0033] The average value of multiple raw baseline dissolved oxygen data is output as the baseline dissolved oxygen data after removing outliers and noise interference; the average value of multiple raw dissolved oxygen data to be measured is output as the dissolved oxygen data to be measured.

[0034] Optionally, step S1 may further include multiple preset temperatures of the oxygen-dissolving medium;

[0035] In step S2, the temperature and dissolved oxygen content of the dissolved oxygen medium are adjusted; the dissolved oxygen medium temperature information, reference dissolved oxygen information and dissolved oxygen information to be tested are traversed at all preset temperatures and at all preset dissolved oxygen contents, and the same pair of dissolved oxygen medium temperature information, reference dissolved oxygen information and dissolved oxygen information to be tested is taken as a group of detection information.

[0036] Optionally, the thermostatic bath device is sealed before step S2.

[0037] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0038] The dissolved oxygen sensor calibration system and method provided in this disclosure use a constant temperature bath to store the dissolved oxygen medium. When multiple dissolved oxygen levels are preset, the controller can control the dissolved oxygen regulating device to adjust the oxygen content of the dissolved oxygen medium in the constant temperature bath to each preset dissolved oxygen level sequentially. The sensor to be calibrated and the reference dissolved oxygen sensor detect the dissolved oxygen information of the dissolved oxygen medium at the current preset dissolved oxygen level. After collecting the reference dissolved oxygen information and the dissolved oxygen information of the dissolved oxygen medium at all preset dissolved oxygen levels, the controller uses the same pair of reference dissolved oxygen information and the dissolved oxygen information of the dissolved oxygen medium as a group of detection information. The sensor to be calibrated is then calibrated based on multiple groups of these detection information.

[0039] This invention discloses a controller that controls the dissolved oxygen content of the dissolved oxygen medium to reach various preset dissolved oxygen levels, and achieves automatic adjustment, automatic detection, and automatic calibration. This enables rapid and accurate calibration of the dissolved oxygen sensor, effectively improving calibration efficiency and reliability. It is suitable for oxygen sensor calibration in various application scenarios, has significant application value and promotion prospects, and has advantages such as simple structure, good stability and reliability. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention, but not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of a dissolved oxygen sensor calibration system provided as an embodiment of the present invention;

[0042] Figure 2 A flowchart of a dissolved oxygen sensor calibration method provided as an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0045] Figure 1 A schematic diagram of a dissolved oxygen sensor calibration system provided in an embodiment of the present invention includes a constant temperature bath device 1, a dissolved oxygen regulating device 2, a sensor to be calibrated 3, a reference dissolved oxygen sensor 4, and a controller 5: the dissolved oxygen regulating device 2 is connected to the constant temperature bath device 1, the sensor to be calibrated 3 and the reference dissolved oxygen sensor 4 are installed in the constant temperature bath device 1, and the controller 5 is connected to the dissolved oxygen regulating device 2, the sensor to be calibrated 3, and the reference dissolved oxygen sensor 4;

[0046] The thermostatic bath device 1 has an internal cavity that can store dissolved oxygen medium. The thermostatic bath device 1 can be a rectangular box structure. In order to keep the temperature, insulation material is installed around the thermostatic bath device 1. The thermostatic bath device 1 has an inlet and an outlet to facilitate adding or releasing dissolved oxygen medium into the thermostatic bath device.

[0047] The dissolved oxygen regulating device 2 can adjust the dissolved oxygen content of the dissolved oxygen medium. It can reduce the dissolved oxygen content by introducing nitrogen gas, or increase the dissolved oxygen content by introducing air or oxygen gas. Specifically, the dissolved oxygen regulating device 2 includes an oxygen-reducing component 21 and an oxygen-increasing component 22. Both the oxygen-reducing component 21 and the oxygen-increasing component 22 are installed in the constant temperature bath device 1. The oxygen-reducing component 21 can increase the dissolved oxygen content of the dissolved oxygen medium by reducing the oxygen content with nitrogen gas. The oxygen-increasing component 22 can increase the dissolved oxygen content of the dissolved oxygen medium. The oxygen-reducing component 21 and the oxygen-increasing component 22 are also connected to a controller 5, which controls the oxygen-reducing component 21 to reduce the dissolved oxygen content of the dissolved oxygen medium, or controls the oxygen-increasing component 22 to increase the dissolved oxygen content of the dissolved oxygen medium.

[0048] In one specific implementation, the oxygen reduction component 21 includes a nitrogen source 211, a first solenoid valve 212, and a first gas flow meter 213. The first solenoid valve 212 and the first gas flow meter 213 are connected in series between the nitrogen source 211 and the constant temperature bath device 1. Both the first solenoid valve 212 and the first gas flow meter 213 are connected to the controller 5. The controller 5 can control the opening of the first solenoid valve 212 to adjust the flow rate of nitrogen gas introduced into the dissolved oxygen medium, while simultaneously monitoring the first gas flow meter 213 for feedback adjustment. The nitrogen source 211 can be a nitrogen cylinder or other external pipeline to input nitrogen gas, and the purity of the nitrogen gas is greater than or equal to 99.999%. The controller 5 can adjust the nitrogen gas flow rate to a set stable flow rate into the dissolved oxygen medium through precise mass flow rate regulation. The gas flow rate can be set between 80 ml / min and 120 ml / min, and this flow rate can be adjusted according to parameters such as the specific substance of the dissolved oxygen medium, the aeration method, and the number of aeration heads. The nitrogen pipe can extend to the bottom of the constant temperature bath device 1, and a venting stone is installed at the end of the nitrogen pipe.

[0049] In another specific embodiment, the oxygenation component 22 includes an oxygen source 221, a second solenoid valve 222, and a second gas flow meter 223. The second solenoid valve 222 and the second gas flow meter 223 are connected in series between the oxygen source 221 and the constant temperature bath device 1. Both the second solenoid valve 222 and the second gas flow meter 223 are connected to the controller 5. The oxygen source can be an oxygen cylinder or other external pipelines that supply oxygen or air. The controller 5 can control the opening of the second solenoid valve 222 to adjust the flow rate of oxygen or air introduced into the dissolved oxygen medium, while simultaneously monitoring the second gas flow meter 223 for feedback adjustment. The controller 5 can use precision mass flow rate adjustment to allow air to be introduced into the dissolved oxygen medium at a set stable flow rate. The gas flow rate can be set between 80 ml / min and 120 ml / min, and this flow rate can be adjusted according to parameters such as the specific substance of the dissolved oxygen medium, the aeration method, and the number of aeration heads. The air pipe can extend to the bottom of the constant temperature bath device 1, and a venting stone is installed at the end of the air pipe.

[0050] The sensor to be calibrated, 3, can detect the dissolved oxygen information of the dissolved oxygen medium, while the reference dissolved oxygen sensor, 4, can detect the reference dissolved oxygen information of the dissolved oxygen medium. The signals detected by the sensor to be calibrated, 3, and the reference dissolved oxygen sensor, 4, are transmitted to the controller, 5, and compared with the reference dissolved oxygen information detected by the reference dissolved oxygen sensor, thereby calibrating the signal of the sensor to be calibrated, 3. The reference dissolved oxygen sensor, 4, can be a fluorescent oxygen sensor.

[0051] The controller 5 can control the dissolved oxygen regulating device 2 to adjust the oxygen content of the dissolved oxygen medium in the constant temperature bath device 1. It can traverse the reference dissolved oxygen information and the dissolved oxygen information to be measured when the dissolved oxygen medium is at all preset dissolved oxygen levels. The same pair of reference dissolved oxygen information and the dissolved oxygen information to be measured is used as a group of detection information. The sensor to be calibrated 3 is calibrated based on multiple groups of detection information.

[0052] The preset dissolved oxygen values ​​include dissolved oxygen values ​​in a zero-oxygen state and dissolved oxygen values ​​in a saturated oxygen state. When the dissolved oxygen medium is in a zero-oxygen state, the sensor to be calibrated 3 detects the dissolved oxygen information to be measured, and the reference dissolved oxygen sensor 4 detects the reference dissolved oxygen information, which serves as zero-point calibration data. When the dissolved oxygen medium is in a saturated oxygen state, the sensor to be calibrated 3 detects the dissolved oxygen information to be measured, and the reference dissolved oxygen sensor 4 detects the reference dissolved oxygen information, which serves as saturated oxygen calibration data. The controller 5 can calibrate the sensor to be calibrated 3 by comparing the zero-point calibration data and the saturated oxygen calibration data. The preset dissolved oxygen values ​​may also include multiple intermediate dissolved oxygen values; adding multiple sets of data can improve the calibration accuracy.

[0053] In another embodiment, the detection information group can also include dissolved oxygen medium temperature information, and the constant temperature bath device 1 can also adjust the temperature of the dissolved oxygen medium to reach multiple preset dissolved oxygen medium temperatures; a heating device 7 is installed in the constant temperature bath device 1, and the heating device 7 is connected to the controller 5; the controller 5 can traverse the reference dissolved oxygen information and the dissolved oxygen information to be measured at all preset temperatures and all preset dissolved oxygen amounts; the detection information group includes dissolved oxygen medium temperature information, reference dissolved oxygen information, and dissolved oxygen information to be measured.

[0054] For example, the dissolved oxygen medium temperature is controlled from 0 to 40°C, and 10 temperature points are selected in a stepped manner. The controller 5 can control the constant temperature bath device 1 to change the dissolved oxygen medium temperature to the lowest temperature point, and then introduce nitrogen into the oxygen component 21 to reduce the dissolved oxygen level to zero. After detecting the reference dissolved oxygen information and the dissolved oxygen information to be measured, the dissolved oxygen medium temperature information, the reference dissolved oxygen information, and the dissolved oxygen information to be measured are grouped into a detection information group. The controller 5 controls the oxygenation component 22 to introduce air to increase the dissolved oxygen level to the next preset dissolved oxygen level, and then detects the reference dissolved oxygen information and the dissolved oxygen information to be measured again. The detection information groups are stored until all preset dissolved oxygen levels are detected. Then, the controller 5 controls the constant temperature bath device 1 to raise the temperature of the dissolved oxygen medium to the second temperature point. The above method is repeated to collect all preset dissolved oxygen levels at that temperature point until all preset temperature and all preset dissolved oxygen levels are collected. These detection information groups are then handed over to the controller 5 to calibrate the sensor 3 to be calibrated. Generally, this sensor not only includes dissolved oxygen information but is also bound to temperature, so the temperature influence factor is also included in the sensor calibration.

[0055] Optionally, the constant temperature bath device 1 is also equipped with a sealing device, which can control the constant temperature bath device to be sealed or open; the function of the sealing device is to prevent external gas from entering on the one hand, and to prevent the filled gas from flowing out on the other hand; the constant temperature bath device 1 is also equipped with a pressure sensor 6 connected to the controller, which can detect pressure changes in the constant temperature bath device 1. After the constant temperature bath device 1 exchanges air with the outside air, it will interfere with the temperature and oxygen content of the dissolved oxygen medium in the constant temperature bath device 1.

[0056] See Figure 2 As shown, the present invention also provides a calibration method based on the above-described dissolved oxygen sensor calibration system, comprising the following steps;

[0057] S1. Multiple preset dissolved oxygen amounts for the oxygen-dissolving medium; if necessary, multiple preset temperatures for the oxygen-dissolving medium may also be required; in this embodiment, water is used as an example of the oxygen-dissolving medium.

[0058] The water temperature is controlled between 0 and 40℃, and the preset temperature can be selected from 10 temperature points in a stepped manner.

[0059] The preset dissolved oxygen content includes the dissolved oxygen content when the dissolved oxygen medium is in a zero oxygen state and the dissolved oxygen content when the dissolved oxygen medium is in a saturated oxygen state.

[0060] S2. Adjust the dissolved oxygen content of the dissolved oxygen medium, traverse the baseline dissolved oxygen information and the dissolved oxygen information to be tested when the dissolved oxygen medium is at all preset dissolved oxygen content, and take the same pair of baseline dissolved oxygen information and the dissolved oxygen information to be tested as a group of detection information.

[0061] In this specific implementation of step one, the controller 5 controls the dissolved oxygen regulating device 2 to introduce nitrogen gas into the dissolved oxygen medium until the reference dissolved oxygen sensor 4 detects that the oxygen content of the dissolved oxygen medium has reached the preset dissolved oxygen level with the lowest dissolved oxygen content; for example, the dissolved oxygen level that reaches the zero oxygen state.

[0062] The controller 5 controls the dissolved oxygen regulating device 2 to increase the dissolved oxygen content of the dissolved oxygen medium in stages. When the dissolved oxygen content in the dissolved oxygen medium is at the preset dissolved oxygen content, the reference dissolved oxygen information detected by the reference dissolved oxygen sensor 4 is obtained, and the sensor to be calibrated 3 detects the dissolved oxygen information to be measured.

[0063] The same pair of baseline dissolved oxygen information and the dissolved oxygen information to be measured are treated as a group of detection information.

[0064] In another specific implementation of this step, in order to improve the accuracy of information monitoring and to remove abnormal signals and noise interference, obtaining the reference dissolved oxygen information detected by the reference dissolved oxygen sensor 4 and the dissolved oxygen information to be measured detected by the sensor to be calibrated 3 includes:

[0065] The reference dissolved oxygen sensor 4 detects multiple raw reference dissolved oxygen information, and the sensor to be calibrated 3 detects multiple raw dissolved oxygen information to be measured.

[0066] The average value of multiple raw baseline dissolved oxygen data is output as the baseline dissolved oxygen data after removing outliers and noise interference; the average value of multiple raw dissolved oxygen data to be measured is output as the dissolved oxygen data to be measured.

[0067] In another embodiment, in step S2, the temperature and dissolved oxygen content of the dissolved oxygen medium are adjusted; the dissolved oxygen medium temperature information, reference dissolved oxygen information, and target dissolved oxygen information are iterated through all preset temperatures and at all preset dissolved oxygen contents, and the same pair of dissolved oxygen medium temperature information, reference dissolved oxygen information, and target dissolved oxygen information is grouped into a detection information group. By adding dissolved oxygen medium temperature information, the accuracy of dissolved oxygen content detection at various temperatures can be corrected.

[0068] S3. The sensor to be calibrated is calibrated based on multiple sets of detection information.

[0069] In a preferred embodiment of the present invention, based on the above-described calibration system and calibration method, the specific operation method includes:

[0070] Multiple preset dissolved oxygen amounts for the dissolved oxygen medium; if necessary, multiple preset temperatures for the dissolved oxygen medium also need to be preset.

[0071] Place the sensor to be calibrated 3 and the reference dissolved oxygen sensor 4 into the constant temperature bath device 1, connect the communication line of the sensor to the controller 5, and inject dissolved oxygen medium into the constant temperature bath device 1 through the water inlet. When the dissolved oxygen medium level does not exceed the head of the sensor, the constant temperature bath device 1 can be sealed with a plug, mainly for the purpose of heat preservation and reducing gas exchange.

[0072] Once the first temperature point is set on the display screen of controller 5, controller 5 sends a command to control the thermostat bath 1 to reach the set first temperature. This temperature is maintained for 5 minutes. Then, controller 5 controls the opening of the first solenoid valve 212 in the oxygen assembly 21, allowing high-purity nitrogen gas to fill the dissolved oxygen medium in the thermostat bath 1. Simultaneously, by monitoring the flow rate of the first gas flow meter 213, nitrogen gas is regulated to a set stable flow rate of 100 ml / min into the dissolved oxygen medium. During the gas flow into the chamber, a pressure sensor monitors the pressure changes within the thermostat bath 1 to ensure the pressure remains stable within the set range. After high-purity nitrogen gas flows in the dissolved oxygen medium for a certain period of time, when the dissolved oxygen sensor 4 displays a reading of zero, the controller 5 closes the first solenoid valve 212 to stop nitrogen from entering the constant temperature bath 1. To ensure that the oxygen content in the constant temperature bath 1 reaches a stable zero-oxygen state, the controller 5 begins to control the sensor to be calibrated 3 and the reference dissolved oxygen sensor 4 to collect data at a rate of 10 data points per second, while simultaneously recording the temperature, pressure, and other parameters in the constant temperature bath 1 as detection information. After collecting a certain number of data points (200), the controller 5 processes the collected data, removes outliers and noise interference, calculates the average output value of the sensor to be calibrated 3 under zero-oxygen conditions, uses this as the zero-point reference value at the current temperature of the sensor to be calibrated 3, and records and stores this zero-point calibration data and the comparison data.

[0073] Then, controller 5 controls the second solenoid valve 222 in the oxygenation component 22 to open, allowing air to fill the dissolved oxygen medium in the constant temperature bath 1. The air flow rate is adjusted by monitoring the flow rate of the second gas flow meter 223 to maintain a set stable flow rate into the dissolved oxygen medium. During the gas flow into the chamber, the pressure sensor monitors the pressure changes within the chamber of the constant temperature bath 1 to ensure the pressure remains stable within the set range. After the gas has flowed stably for a certain period, the data from the reference dissolved oxygen sensor 4 stabilizes. At this point, controller 5 begins to control the sensor to be calibrated 3 and the reference dissolved oxygen sensor 4 to acquire data, collecting 10 data points per second, and simultaneously recording the temperature, pressure, and other parameter values ​​within the constant temperature bath 1 as detection information. After collecting a certain number of data points (200), controller 5 processes the collected data, removing outliers and noise interference, calculating the average output value of the sensor to be calibrated 3 under saturated oxygen conditions, using this as the zero-point reference value at the current temperature of the sensor to be calibrated 3, and recording and storing this zero-point calibration data and the comparison data.

[0074] Once the second temperature point is set on the controller, repeat the above process.

[0075] At all preset temperatures, the dissolved oxygen medium temperature information, reference dissolved oxygen information, and the dissolved oxygen to be measured information at all preset dissolved oxygen levels are used to calibrate the sensor 3 to be calibrated for instrument calibration and temperature calibration. If the reading of the reference dissolved oxygen sensor 4 is greater than twice the saturated dissolved oxygen concentration at the currently set temperature, the device will automatically stop, and calibration will begin again at this temperature point.

[0076] In summary, this disclosure uses controller 5 to control the dissolved oxygen content of the dissolved oxygen medium to achieve various preset dissolved oxygen levels, and realizes automatic adjustment, automatic detection, and automatic calibration. This enables rapid and accurate calibration of the dissolved oxygen sensor, effectively improving calibration efficiency and reliability. It is suitable for oxygen sensor calibration in various application scenarios, has significant application value and promotion prospects, and has advantages such as simple structure, good stability and reliability. At the same time, it eliminates the need to use Na2SO3, thus avoiding harm to personnel and pollution to the environment.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dissolved oxygen sensor calibration system, characterized in that, Includes the following components: Thermostatic bath device, capable of storing dissolved oxygen medium; A dissolved oxygen regulating device, connected to the constant temperature bath, is capable of adjusting the dissolved oxygen content of the dissolved oxygen medium. The sensor to be calibrated is installed in the constant temperature bath device and is capable of detecting the dissolved oxygen information of the dissolved oxygen medium. A reference dissolved oxygen sensor, installed in the constant temperature bath, is capable of detecting the reference dissolved oxygen information of the dissolved oxygen medium. The controller is connected to the dissolved oxygen regulating device, the sensor to be calibrated, and the reference dissolved oxygen sensor. It can control the dissolved oxygen regulating device to adjust the oxygen content of the dissolved oxygen medium in the constant temperature bath. It can traverse the reference dissolved oxygen information and the dissolved oxygen information to be measured when the dissolved oxygen medium is at all preset dissolved oxygen levels. The same pair of reference dissolved oxygen information and the dissolved oxygen information to be measured is used as a group of detection information. The sensor to be calibrated is calibrated based on multiple groups of detection information.

2. The dissolved oxygen sensor calibration system according to claim 1, characterized in that, The dissolved oxygen regulating device includes the following components: The oxygen reduction component can increase the dissolved oxygen content of the dissolved oxygen medium by reducing the oxygen content through nitrogen gas. An oxygenation component is used to increase the dissolved oxygen content of the dissolved oxygen medium. Both the oxygen-reducing component and the oxygen-enhancing component are installed in the constant temperature bath device.

3. The dissolved oxygen sensor calibration system according to claim 1, characterized in that, The preset dissolved oxygen levels include dissolved oxygen levels when the dissolved oxygen medium is in a zero-oxygen state and dissolved oxygen levels when the dissolved oxygen medium is in a saturated oxygen state.

4. The dissolved oxygen sensor calibration system according to claim 1, characterized in that, The constant temperature bath device can also adjust the temperature of the dissolved oxygen medium to reach multiple preset dissolved oxygen medium temperatures. The controller can traverse the baseline dissolved oxygen information and the dissolved oxygen information to be measured at all preset temperatures and all preset dissolved oxygen levels. Each of the aforementioned detection information groups includes dissolved oxygen medium temperature information, baseline dissolved oxygen information, and dissolved oxygen information to be measured.

5. The dissolved oxygen sensor calibration system according to claim 1, characterized in that, The constant temperature bath device is also equipped with a sealing device, which can control the constant temperature bath device to be sealed or open. The constant temperature bath device is also equipped with a pressure sensor connected to the controller.

6. The calibration method for the dissolved oxygen sensor calibration system according to claim 1, characterized in that, Includes the following steps; S1, multiple preset dissolved oxygen amounts for preset dissolved oxygen media; S2. Adjust the dissolved oxygen content of the dissolved oxygen medium, traverse the baseline dissolved oxygen information and the dissolved oxygen information to be tested when the dissolved oxygen medium is at all preset dissolved oxygen content, and take the same pair of baseline dissolved oxygen information and the dissolved oxygen information to be tested as a group of detection information. S3. The sensor to be calibrated is calibrated based on multiple sets of detection information.

7. The calibration method according to claim 6, characterized in that, The step S2 comprises: The controller controls the dissolved oxygen regulating device to introduce nitrogen into the dissolved oxygen medium until the reference dissolved oxygen sensor detects that the oxygen content of the dissolved oxygen medium has reached the preset dissolved oxygen content with the lowest dissolved oxygen content. The controller periodically controls the dissolved oxygen regulating device to increase the dissolved oxygen content of the dissolved oxygen medium. When the dissolved oxygen content in the dissolved oxygen medium is at a preset dissolved oxygen content, the reference dissolved oxygen information detected by the reference dissolved oxygen sensor is obtained, and the sensor to be calibrated detects the dissolved oxygen information to be measured. The same pair of baseline dissolved oxygen information and the dissolved oxygen information to be measured are treated as a group of detection information.

8. The calibration method according to claim 7, characterized in that, The process of obtaining the baseline dissolved oxygen information detected by the baseline dissolved oxygen sensor and the dissolved oxygen information to be measured detected by the sensor to be calibrated includes: The reference dissolved oxygen sensor detects multiple raw reference dissolved oxygen information, while the sensor to be calibrated detects multiple raw dissolved oxygen information to be measured. The average value of multiple raw baseline dissolved oxygen data is output as the baseline dissolved oxygen data after removing outliers and noise interference; the average value of multiple raw dissolved oxygen data to be measured is output as the dissolved oxygen data to be measured.

9. The calibration method according to claim 6, characterized in that, Step S1 also includes multiple preset temperatures for the oxygen-dissolving medium; In step S2, the temperature of the dissolved oxygen medium and the amount of dissolved oxygen in the dissolved oxygen medium are adjusted. The dissolved oxygen medium temperature information, reference dissolved oxygen information, and test dissolved oxygen information are traversed at all preset temperatures and when the dissolved oxygen medium is at all preset dissolved oxygen levels. The same pair of dissolved oxygen medium temperature information, reference dissolved oxygen information, and test dissolved oxygen information is taken as a group of detection information.

10. The calibration method according to claim 6, characterized in that, Before step S2, the thermostatic bath device is sealed.

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