阅读说明：本技术 一种三参数智能补偿校正电化学在线溶解氧传感器 (Three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor ) 是由 秦宏鹏 陈娟 刘翔宇 于 2018-08-29 设计创作，主要内容包括：本发明公开一种三参数智能补偿校正电化学在线溶解氧传感器,包括溶解氧电极、电导率传感器、大气压力传感器、温度电极、被测水样流通池、传感器支架及检测电路单元,所述溶解氧电极包括传感器的外壳、透氧膜、膜盖、金电极、银电极、铂电极、液态反应电解液、电极基座及绝缘导线；所述溶解氧电极、电导率传感器、大气压力传感器、温度电极分别通过绝缘导线接入检测电路单元进行信号处理；所述检测电路单元包括极化电压电路,溶解氧信号检测电路,电导率、大气压力、温度补偿电路,串口通讯电路等。本发明对影响溶解氧检测浓度的电导率、大气压力、温度同时进行补偿标定,大大提高了检测的准确性,且响应速度快,精度高,寿命长,稳定性好。(The invention discloses a three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor, which comprises a dissolved oxygen electrode, a conductivity sensor, an atmospheric pressure sensor, a temperature electrode, a measured water sample flow cell, a sensor support and a detection circuit unit, wherein the dissolved oxygen electrode comprises a shell of the sensor, an oxygen permeable membrane, a membrane cover, a gold electrode, a silver electrode, a platinum electrode, liquid reaction electrolyte, an electrode base and an insulated wire; the dissolved oxygen electrode, the conductivity sensor, the atmospheric pressure sensor and the temperature electrode are respectively connected to the detection circuit unit through insulated wires for signal processing; the detection circuit unit comprises a polarization voltage circuit, a dissolved oxygen signal detection circuit, a conductivity, atmospheric pressure and temperature compensation circuit, a serial port communication circuit and the like. The invention simultaneously carries out compensation calibration on the conductivity, the atmospheric pressure and the temperature which influence the detection concentration of the dissolved oxygen, greatly improves the detection accuracy, and has the advantages of high response speed, high precision, long service life and good stability.)

1. A three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor comprises a dissolved oxygen electrode (1), a conductivity sensor (30), an atmospheric pressure sensor (24), a temperature electrode (33), a measured water sample flow cell (35), a sensor support (26) and a detection circuit unit, wherein the dissolved oxygen electrode comprises a cylindrical shell (2) of the sensor, an oxygen permeable membrane (3), a membrane cover (4), a gold electrode (5) serving as a working electrode, a silver electrode (6) serving as an auxiliary electrode, a platinum electrode (7) serving as a silver protection electrode, liquid reaction electrolyte (8), an electrode base (9) and an insulated lead (10); the conductivity sensor (30) comprises a conductivity detection unit (31) and a conductivity signal conductor (32); a dissolved oxygen electrode bracket hole (27), a conductivity sensor bracket hole (28) and a temperature electrode bracket hole (29) are formed in the sensor bracket (26); the dissolved oxygen electrode (1), the conductivity sensor (30), the atmospheric pressure sensor (24) and the temperature electrode (33) are respectively connected to the measuring circuit unit through an insulated conducting wire (10), a conductivity signal wire (32), an atmospheric pressure sensor signal wire (25) and a temperature electrode signal wire (34); be provided with water inlet (36), governing valve (37), nozzle (38), flowmeter (39), outlet (40) on being surveyed water sample flow cell (35), its characterized in that: the dissolved oxygen electrode (1), the conductivity sensor (30) and the temperature electrode (33) are connected into the measured water sample flow cell (35) through support holes in the sensor support (26), and the atmospheric pressure sensor (24) is placed in the same atmospheric environment as the measured water sample flow cell (35).

2. The three-parameter intelligent compensation and correction electrochemical online dissolved oxygen sensor as claimed in claim 1, wherein: the detection circuit unit comprises a dissolved oxygen electrode polarization circuit (11), a current-to-voltage circuit (12), a voltage amplification circuit (17), a filter circuit (16), a temperature compensation circuit (13), a conductivity compensation circuit (14), an atmospheric pressure compensation circuit (15), an AD conversion circuit (18), an STM32F103ZET6 microcontroller (19), a serial port communication circuit (22), a liquid crystal display circuit (21), a storage unit (20) and a relay control circuit (23).

3. The three-parameter intelligent compensation and correction electrochemical online dissolved oxygen sensor as claimed in claim 1, wherein: the temperature electrode (33) not only compensates and calibrates the measured value of the dissolved oxygen electrode (1) through the temperature compensation circuit (13), but also compensates and calibrates the measured value of the conductivity sensor (30).

4. The three-parameter intelligent compensation and correction electrochemical online dissolved oxygen sensor as claimed in claim 1, wherein: the nozzle is opposite to the lower end of the dissolved oxygen electrode (1) and can directly spray the detected water sample to the oxygen permeable membrane (3).

5. The three-parameter intelligent compensation and correction electrochemical online dissolved oxygen sensor as claimed in claim 1, wherein: the gold electrode (5) is a cap-shaped gold cylinder, and the lower end of the gold electrode is a convex cambered surface with a nano porous structure.

Technical Field

The invention relates to the field of dissolved oxygen content detection, in particular to a three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor.

Background

The dissolved oxygen is molecular oxygen dissolved in liquid water, is used as a key index for evaluating water pollution and water quality, and is a key index in the fields of water quality detection, sewage treatment, food fermentation, aquatic products, clinical diagnosis and the like. The concentration of oxygen dissolved in drinking water is not lower than 6 mg/L. When the concentration of dissolved oxygen in the ecological system is lower than 4mg/L, the fish die due to anoxic suffocation. In the field of food fermentation, controlling dissolved oxygen concentration is an important consideration for ensuring microbial growth. In the field of clinical diagnosis, diseases can be diagnosed by knowing the metabolic state of cells and tissues by knowing the concentration of dissolved oxygen in the cells. In the sewage treatment field, the dissolved oxygen is detected, so that the sewage treatment efficiency can be improved, and the operation cost is reduced. In the fields of thermal power generation, nuclear power generation and the like, the dissolved oxygen concentration detection of the high-temperature boiler feed water can improve the operation efficiency and safety of a factory and effectively prevent potential accidents.

The existing electrochemical dissolved oxygen electrodes mostly have the following technical problems: (1) the calibration of the sensor before detection needs manual operation and cannot be automatically calibrated. (2) The detection process is greatly influenced by environmental parameters, and the real-time compensation and calibration of the change of the environmental parameters cannot be carried out. (3) The anti-interference capability is poor, and the detection data is inaccurate. (4) The unreasonable structural design of the working electrode causes poor response speed, accuracy and stability of the sensor.

Disclosure of Invention

Aiming at the problems in the existing electrochemical dissolved oxygen sensing detection technology, the invention aims to provide a three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor, which can automatically detect the numerical values of three main environmental parameters influencing the detection of dissolved oxygen before detection, and calibrate the temperature parameter, the conductivity parameter, the atmospheric pressure parameter and the dissolved oxygen electrode measurement curve of the sensor before detection, so that the electrochemical dissolved oxygen sensor can quickly and accurately measure the concentration value of the dissolved oxygen.

In order to achieve the above purposes, the invention adopts the technical scheme that: a three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor comprises a dissolved oxygen electrode, a conductivity sensor, an atmospheric pressure sensor, a temperature electrode, a measured water sample flow cell, a sensor support and a detection circuit unit, wherein the dissolved oxygen electrode comprises a cylindrical shell of the sensor, an oxygen permeation membrane, a membrane cover, a gold electrode serving as a working electrode, a silver electrode serving as an auxiliary electrode, a platinum electrode serving as a silver protection electrode, liquid reaction electrolyte, an electrode base and an insulated lead; the conductivity sensor comprises a conductivity detection unit and a conductivity signal lead; the sensor bracket is provided with a dissolved oxygen electrode bracket hole, a conductivity sensor bracket hole and a temperature electrode bracket hole; the dissolved oxygen electrode, the conductivity sensor, the atmospheric pressure sensor and the temperature electrode are respectively connected to the measuring circuit unit through an insulated conducting wire, a conductivity signal wire, an atmospheric pressure sensor signal wire and a temperature electrode signal wire; be provided with water inlet, governing valve, nozzle, flowmeter, outlet on the survey water sample flow cell, its characterized in that: the dissolved oxygen electrode, the conductivity sensor and the temperature electrode are connected into the measured water sample flow cell through a bracket hole on the sensor bracket, and the atmospheric pressure sensor is arranged in the same atmospheric environment with the measured water sample flow cell.

Furthermore, the detection circuit unit comprises a dissolved oxygen electrode polarization circuit, a current-to-voltage circuit, a voltage amplification circuit, a filter circuit, a temperature compensation circuit, a conductivity compensation circuit, an atmospheric pressure compensation circuit, an AD conversion circuit, an STM32F103ZET6 microcontroller, a serial communication circuit, a liquid crystal display circuit, a storage unit and a relay control circuit.

Furthermore, the temperature electrode not only compensates and calibrates the measured value of the dissolved oxygen electrode through the temperature compensation circuit, but also compensates and calibrates the measured value of the conductivity sensor.

Furthermore, the nozzle is opposite to the lower end of the dissolved oxygen electrode and can directly spray the detected water sample to the oxygen permeable membrane.

Furthermore, the gold electrode is a hat-shaped gold cylinder, and the lower end of the gold electrode is a convex cambered surface with a nano porous structure.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages and effects:

1. the invention relates to a three-parameter intelligent compensation correction electrochemical online dissolved oxygen sensor, which is a three-electrode detection system synthesized based on a gold electrode serving as a working electrode, a silver electrode serving as an auxiliary electrode and a platinum electrode serving as a silver protection electrode, wherein an oxygen permeable membrane isolates a detected water sample from electrolyte, when a constant voltage of 0.6-0.8V is provided between the gold electrode and the silver electrode, a diffusion current is generated between the gold electrode and the silver electrode, the magnitude of the diffusion current is in direct proportion to the dissolved oxygen concentration in the detected water sample, and the dissolved oxygen concentration can be known by measuring the magnitude of the diffusion current. Because the invention adopts the three-parameter (temperature, conductivity and atmospheric pressure) compensation calibration method, the calibration efficiency and accuracy of the dissolved oxygen sensor can be improved before detection, the main parameters influencing the detection of the concentration of the dissolved oxygen can be compensated in real time in the detection process, the anti-interference capability of the dissolved oxygen sensor is greatly improved, and the detection data is more accurate.

2. Because the detection circuit unit adopted by the invention comprises a dissolved oxygen electrode polarization circuit, a current-to-voltage circuit, a voltage amplification circuit, a filter circuit, a temperature compensation circuit, a conductivity compensation circuit, an atmospheric pressure compensation circuit, an AD conversion circuit, an STM32F103ZET6 microcontroller, a serial communication circuit, a liquid crystal display circuit, a storage unit and a relay control circuit, the detection signal is more accurate and can be displayed on a liquid crystal display screen in real time, all data are stored in a nonvolatile memory, the data cannot be lost after power failure, and the serial communication circuit can enable a sensor to download the data into a computer.

3. The temperature electrode adopted by the invention not only compensates and calibrates the measured value of the dissolved oxygen electrode through the temperature compensation circuit, but also compensates and calibrates the measured value of the conductivity sensor, thereby improving the detection precision of the conductivity and simultaneously improving the accuracy of the dissolved oxygen conductivity compensation.

4. Because the bottom of the measured water sample flow cell is provided with the nozzle, the measured water sample realizes high flow rate on the oxygen permeable membrane of the dissolved oxygen electrode through the nozzle, and the high flow rate can greatly reduce the response time of the sensor.

5. Because the gold electrode adopted by the invention is a cap-shaped gold cylinder, and the lower end of the gold electrode is a convex cambered surface with a nano porous structure, the contact area of the working electrode and the electrolyte is increased by 150 times, and the response speed and the stability of the dissolved oxygen sensor are improved.

Drawings

FIG. 1 is a schematic view of a disassembled structure of a dissolved oxygen electrode of the present invention.

FIG. 2 is a schematic diagram of a measurement circuit unit according to the present invention.

Fig. 3 is a schematic view of the structure of the atmospheric pressure sensor of the present invention.

FIG. 4 is a structural diagram of a sensor support according to the present invention.

FIG. 5 is a schematic view of the working structure of the measured water sample flow cell of the present invention.

In the figure: 1. a dissolved oxygen electrode; 2. a cylindrical housing; 3. an oxygen permeable membrane; 4. a membrane cover; 5. a gold electrode; 6. a silver electrode; 7. a platinum electrode; 8. liquid reaction electrolyte; 9. an electrode base; 10. a dissolved oxygen electrode insulated wire; 11. an electrode polarization circuit; 12. a current to voltage circuit; 13. a temperature compensation circuit; 14. a conductivity compensation circuit; 15. an atmospheric pressure compensation circuit; 16. a filter circuit; 17. a voltage amplifying circuit; 18. an AD conversion circuit; 19. STM32F103ZET6 microcontroller; 20. a storage unit; 21. a relay control circuit; 22. a serial communication circuit; 23. a relay control circuit; 24. an atmospheric pressure sensor; 25. an atmospheric pressure sensor signal line; 26. a sensor holder; 27. a dissolved oxygen electrode support aperture; 28. a conductivity sensor support aperture; 29. a temperature electrode support aperture; 30. a conductivity sensor; 31. a conductivity detection unit; 32. a conductivity signal line; 33. a temperature electrode; 34. a temperature electrode signal line; 35. a measured water sample flow cell; 36. a water inlet; 37. adjusting a valve; 38. a nozzle; 39. a flow meter; 40. and (7) a water outlet.

Detailed Description

The invention is further described with reference to the following figures and detailed description.