Digital dissolved oxygen sensor

Abstract

The utility model relates to the technical field of water quality detection equipment, in particular to a digital dissolved oxygen sensor. The device comprises a fluorescence measurement module and a microcontroller, wherein the fluorescence measurement module comprises a fluorescence receiver, a reference light generator, an exciting light generator and an amplifying circuit. The reference light generator provides a comparison standard, the exciting light generator excites the fluorescence indicator diaphragm to generate fluorescence, and the fluorescence receiver captures and analyzes a fluorescence signal. The amplifying circuit amplifies and conditions the signals and transmits the signals to the microcontroller. The microcontroller records the time and intensity of fluorescence emission, calculates the intensity of fluorescence emission and the loss condition of the indicator, calculates the concentration of dissolved oxygen according to the quenching time and the fluorescence intensity signal of the indicator, and calculates the attenuation condition of the excitation light source through the comparison signal. According to the utility model, the advantages of a fluorescence signal light intensity method and a quenching effect method are combined, the compensation for light source attenuation, fluorescence indicator loss and environmental factors is realized, and the measurement precision and stability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of water quality detection equipment, in particular to a digital dissolved oxygen sensor. Background Art

[0002] Dissolved oxygen sensors have a wide range of applications in environmental monitoring, water treatment, aquaculture, industrial process control, and other fields. The primary function of these sensors is to accurately measure the dissolved oxygen content in water, which is crucial for maintaining ecological balance, protecting the health of aquatic life, and optimizing industrial production processes.

[0003] Dissolved oxygen sensors currently on the market have the following major issues: First, when measuring using the fluorescence signal intensity method, the excitation light source gradually decays over time, causing variations in the intensity of the emitted light, which in turn affects the accuracy of the measurement results. This light source decay phenomenon makes it difficult to guarantee measurement accuracy during long-term use. Second, while the fluorescence signal quenching effect method can avoid the direct impact of light source decay on measurement results, it cannot directly determine the light source's service life, making it difficult for users to replace the light source in a timely manner, potentially leading to deviations in measurement results. Finally, the fluorescent indicator gradually wears out during long-term use, which not only affects measurement results but also increases maintenance costs. However, existing sensors cannot accurately assess the wear status of the fluorescent indicator, making it difficult to predict its service life. Utility Model Content

[0004] The purpose of the utility model is to provide a digital dissolved oxygen sensor to solve the problems in the prior art of low measurement accuracy and inability to judge the life of a lamp source and the loss status of a fluorescent indicator.

[0005] To achieve the above object, a digital dissolved oxygen sensor is provided, comprising a main control circuit and a sensor body, wherein the main control circuit comprises a fluorescence measurement module and a microcontroller, wherein:

[0006] The fluorescence measurement module includes a fluorescence receiver, a reference light generator, an excitation light generator and an amplification circuit;

[0007] The fluorescence receiver is used to receive and analyze the fluorescence signal and calculate the dissolved oxygen concentration by measuring the time and intensity of the fluorescence emission;

[0008] The reference light generator provides a stable light source as a comparison benchmark to eliminate the influence of ambient light or other non-target signals and ensure the accuracy of the measurement;

[0009] The excitation light generator is used to excite the fluorescent indicator membrane to make it emit fluorescence;

[0010] The amplifying circuit is used to amplify and condition the weak signal received by the fluorescence receiver to ensure the integrity and stability of the signal;

[0011] The fluorescence measurement module is connected to a microcontroller for receiving and processing signals from the fluorescence measurement module.

[0012] As a further improvement of the present technical solution, the main control circuit further includes an analog-to-digital converter, a power input module, a programmable power module, a temperature sensor, an internal storage unit and a communication module;

[0013] The analog-to-digital converter is connected to the microcontroller and is used to receive the signal after A / D conversion;

[0014] The power input module is connected to the microcontroller and is used to obtain power supply from the power input module;

[0015] The programmable power module is connected to the microcontroller and is used to provide a bias voltage to adjust the working state of certain electronic devices or improve their performance;

[0016] The temperature sensor is connected to the microcontroller to monitor the ambient temperature and generate a corresponding temperature signal;

[0017] The internal storage unit is connected to the microcontroller and is used to store program codes and configuration parameters;

[0018] The communication module is connected to the microcontroller and is used to transmit dissolved oxygen data to an external device.

[0019] As a further improvement of the present technical solution, the sensor body is provided with an electrode shell body, in which a circuit board integrating various modules is encapsulated, and the bottom of the electrode shell body is fixedly connected to the installer through threads.

[0020] As a further improvement of this technical solution, the top of the electrode shell body is fixedly connected to the connector through a thread, a measuring membrane head is provided in the connector, the top of the connector is fixedly connected to the fixed cover through a thread, and the middle of the connector is fixedly connected to the protective cover through a thread.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This digital dissolved oxygen sensor combines the fluorescence signal intensity method with the quenching effect method. A fluorescence receiver and reference light generator are used to obtain the indicator fluorescence emission intensity signal, eliminating the influence of ambient light and other non-target signals and improving measurement accuracy. The fluorescence receiver and excitation light generator are used to obtain a quenching time signal, recording the timing of fluorescence emission and improving measurement stability. The reference light generator and excitation light generator are used to obtain an excitation light intensity comparison signal, providing a comparison baseline and ensuring measurement accuracy. The coordination of these three units compensates for light source attenuation, fluorescence indicator loss, and environmental factors, improving the accuracy and stability of dissolved oxygen concentration measurements.

[0023] 2. The digital dissolved oxygen sensor also integrates a communication module, a temperature sensor and a programmable power module. The communication module uses the RS-485 interface to realize the functions of long-distance, strong anti-interference and multi-point communication of data, which improves the application range and reliability of the dissolved oxygen sensor. The temperature sensor collects temperature signals and monitors the working environment of the sensor in real time, which improves the accuracy and consistency of the measurement results. The programmable power module enhances the reliability of the sensor and ensures long-term working stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The circuit structure of the utility model includes a schematic block diagram of the working process;

[0025] Figure 2 It is a schematic diagram of the overall structure of the utility model.

[0026] The meaning of each number in the figure is:

[0027] 1. Protective cover; 2. Fixed cover; 3. Connector; 4. Measuring membrane head; 5. Electrode housing body; 6. Installer. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0031] Example 1

[0032] See also Figure 1-Figure 2 As shown, the purpose of this embodiment is to provide a digital dissolved oxygen sensor, including a main control circuit and a sensor body. The main control circuit includes a fluorescence measurement module and a microcontroller (MCU), and the fluorescence measurement module is further divided into a fluorescence receiver, a reference light generator, an excitation light generator and an amplifier circuit. The fluorescence receiver is used to receive and analyze the fluorescence signal and calculate the dissolved oxygen concentration by measuring the time and intensity of the fluorescence emission. The reference light generator provides a stable light source as a comparison benchmark to eliminate the influence of ambient light or other non-target signals and ensure the accuracy of the measurement. The excitation light generator is used to excite the fluorescent indicator diaphragm to emit fluorescence. The fluorescence measurement module is connected to the microcontroller for receiving and processing signals from the fluorescence measurement module. The weak signal received by the fluorescence receiver is amplified and conditioned by the amplifier circuit and enters the microcontroller to ensure the integrity and stability of the signal.

[0033] To further improve performance, the main control circuit also includes an analog-to-digital converter (A / D), a power input module, a programmable power module (bias voltage), a temperature sensor, an internal storage unit (FLASH), and a communication module. The analog-to-digital converter is connected to the microcontroller to receive the signal after A / D conversion. The power input module is connected to the microcontroller to obtain power supply from the power input module. The programmable power module is connected to the microcontroller to provide a bias voltage to adjust the working state of certain electronic components or improve performance. The temperature sensor is connected to the microcontroller to monitor the ambient temperature and generate a corresponding temperature signal. The internal storage unit is connected to the microcontroller to store program code and configuration parameters. The communication module is connected to the microcontroller and the external RS485 interface is used to transmit dissolved oxygen data to external devices.

[0034] The sensor body includes an electrode housing 5, which houses the circuit board integrating the various modules. The lower portion of the electrode housing 5 is threadedly connected to the installer 6, and the upper portion is threadedly connected to the connector 3. The connector 3 houses a measuring membrane 4, which is threadedly connected to the fixing cover 2 at the top and to the protective cover 1 in the middle.

[0035] Working principle:

[0036] During normal measurement, excitation light shines on the fluorescent indicator membrane, generating a fluorescence effect. The fluorescence receiver receives the signal and calculates the quenching time, thereby determining the dissolved oxygen concentration. The program automatically tests the light intensity signal at set intervals, comparing it to a reference light source to calculate the current excitation light source's luminous efficiency. The fluorescence effect intensity also calculates the wear and tear of the fluorescent indicator. The fluorescence dissolved oxygen electrode measures the fluorescence quenching time signal and water temperature. The amplifier circuit and A / D circuit convert the signal into a digital signal that can be processed by a microcontroller. The dissolved oxygen value of the water sample is then determined using a pre-established measurement curve and algorithm. By measuring and calculating the excitation light intensity contrast signal and the indicator fluorescence emission intensity signal, the amplifier circuit converts the current signal into a voltage signal, which is then converted to a digital signal that can be processed by the microcontroller through the A / D circuit. Comparison with the reference light source and the stored initial signal is used to calculate the current attenuation of the excitation light source and its compensation, as well as the current wear and tear of the fluorescent indicator membrane and its lifespan.

[0037] This design combines the advantages of both the fluorescence signal intensity method and the quenching effect method to compensate for light source attenuation, fluorescent indicator loss, and environmental factors, improving measurement accuracy and stability. Furthermore, the integrated communication module, temperature sensor, and programmable power module further enhance the sensor's applicability and reliability.

[0038] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A digital dissolved oxygen sensor, characterized in that: It includes a main control circuit and a sensor body, wherein the main control circuit includes a fluorescence measurement module and a microcontroller, wherein: The fluorescence measurement module includes a fluorescence receiver, a reference light generator, an excitation light generator and an amplification circuit; The fluorescence receiver is used to receive and analyze the fluorescence signal and calculate the dissolved oxygen concentration by measuring the time and intensity of the fluorescence emission; The reference light generator provides a stable light source as a comparison benchmark to eliminate the influence of ambient light or other non-target signals and ensure the accuracy of the measurement; The excitation light generator is used to excite the fluorescent indicator membrane to make it emit fluorescence; The amplifying circuit is used to amplify and condition the weak signal received by the fluorescence receiver to ensure the integrity and stability of the signal; The fluorescence measurement module is connected to a microcontroller for receiving and processing signals from the fluorescence measurement module.

2. The digital dissolved oxygen sensor according to claim 1, characterized in that: The main control circuit also includes an analog-to-digital converter, a power input module, a programmable power module, a temperature sensor, an internal storage unit and a communication module; The analog-to-digital converter is connected to the microcontroller and is used to receive the signal after A / D conversion; The power input module is connected to the microcontroller and is used to obtain power supply from the power input module; The programmable power module is connected to the microcontroller and is used to provide a bias voltage to adjust the working state of certain electronic devices or improve their performance; The temperature sensor is connected to the microcontroller to monitor the ambient temperature and generate a corresponding temperature signal; The internal storage unit is connected to the microcontroller and is used to store program codes and configuration parameters; The communication module is connected to the microcontroller and is used to transmit dissolved oxygen data to an external device.

3. The digital dissolved oxygen sensor according to claim 1, characterized in that: The sensor body is provided with an electrode housing body (5), a circuit board integrating various modules is encapsulated in the electrode housing body (5), and the bottom of the electrode housing body (5) is fixedly connected to the installer (6) via a thread.

4. The digital dissolved oxygen sensor according to claim 3, characterized in that: The top of the electrode housing body (5) is fixedly connected to the connector (3) via a thread, a measuring membrane head (4) is provided in the connector (3), the top of the connector (3) is fixedly connected to the fixing cover (2) via a thread, and the middle of the connector (3) is fixedly connected to the protective cover (1) via a thread.

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