Water quality analyzer

Abstract

The invention discloses a water quality analyzer. The water quality analyzer comprises a detection pool main body, an ultraviolet optical module, a signal detection processing module and a turbidity calculation module; a first optical window and a second optical window which are used for light path penetration are arranged on the detection cell main body, the ultraviolet optical module is positioned on one side, close to the first optical window, of the detection cell main body, and the signal detection processing module is positioned on one side, close to the second optical window, of the detection cell main body; the signal detection processing module is used for acquiring an electric signal of transmitted light passing through a to-be-detected water body according to preset detection sensitivity, and the signal detection processing module is also used for adjusting the preset detection sensitivity according to the change of an environment where the to-be-detected water body is located; and determining the turbidity of the to-be-detected water according to the electric signal of the transmitted light. The water quality analyzer disclosed by the invention can realize low-power-consumption operation and high-precision signal capture, and is relatively high in environmental adaptability and operation stability.

Description

Technical Field

[0001] The present invention relates to the field of water quality testing technology, and in particular to a water quality analyzer. Background Technology

[0002] With increasingly stringent requirements for environmental protection and water quality safety monitoring, ultraviolet absorption spectroscopy has become one of the mainstream analytical techniques in the field of water quality testing due to its advantages such as speed and the absence of chemical reagents.

[0003] Ultraviolet (UV) absorption spectroscopy measures the degree to which a water sample absorbs light signals in a specific UV band, enabling qualitative and quantitative analysis of various pollutants. It has wide applications in drinking water safety, wastewater treatment, industrial emission monitoring, and early warning systems for natural water bodies. However, its core detection performance is highly dependent on the sensitivity, stability, and power consumption of the UV detector.

[0004] Traditional photodetectors, commonly used in existing equipment, have inherent limitations in practical applications, including high power consumption, large dark current, insufficient response to weak signals, and susceptibility of output signals to interference from ambient temperature and humidity. These problems restrict the improvement of detection accuracy and often necessitate complex signal conditioning circuits, increasing system cost, size, and power consumption, making them unsuitable for long-term continuous monitoring in changing environments. Summary of the Invention

[0005] This invention provides a water quality analyzer that achieves low-power operation and high-precision signal capture, simplifies circuit design architecture, reduces equipment manufacturing costs, and improves environmental adaptability and operational stability.

[0006] This invention provides a water quality analyzer, including a detection tank body, an ultraviolet optical module, a signal detection and processing module, and a turbidity calculation module; The detection pool body is provided with a first optical window and a second optical window for light path penetration. The first optical window and the second optical window are arranged facing each other. The detection pool body is used to contain the water body to be detected. The ultraviolet optical module is located on the side of the detection pool body close to the first optical window, and the light emission direction of the ultraviolet optical module is directly opposite to the first optical window. The ultraviolet optical module is used to emit ultraviolet light to the water body to be detected. The signal detection and processing module is located on the side of the detection pool body close to the second optical window. The photosensitive side of the signal detection and processing module is directly opposite the second optical window. The signal detection and processing module is used to acquire the electrical signal of the transmitted light through the water body to be detected according to the preset detection sensitivity and send it to the turbidity calculation module. The signal detection and processing module is also used to adjust the preset detection sensitivity according to the environmental changes of the water body to be detected. The turbidity calculation module is communicatively connected to the signal detection and processing module. The turbidity calculation module is used to acquire the electrical signal of the transmitted light and determine the turbidity of the water body to be detected based on the electrical signal of the transmitted light.

[0007] Optionally, the signal detection and processing module includes a field-effect ultraviolet detector and a gate voltage regulation unit; The photosensitive surface of the field-effect ultraviolet detector serves as the photosensitive side of the signal detection and processing module, and the gate voltage adjustment unit is connected to the gate of the field-effect ultraviolet detector. The gate voltage adjustment unit is used to control the gate voltage of the field-effect ultraviolet detector to control the preset detection sensitivity; the field-effect ultraviolet detector is used to acquire the transmitted light through the water body to be detected, convert the transmitted light into an electrical signal, and amplify the electrical signal.

[0008] Optionally, the field-effect ultraviolet detector includes an n-channel metal-semiconductor field-effect transistor, and the photosensitive surface of the field-effect ultraviolet detector includes silicon carbide or gallium nitride.

[0009] Optionally, the dark current of the field-effect ultraviolet detector is ≤1nA, and the transconductance of the field-effect ultraviolet detector is ≥50mS / mm.

[0010] Optionally, the signal detection and processing module further includes a control unit and a signal amplifier; The first end of the control unit is connected to the gate voltage adjustment unit. The control unit is used to generate a corresponding gate voltage control signal according to the environmental changes of the water body to be detected, and send it to the gate voltage adjustment unit. The gate voltage adjustment unit is specifically used to control the gate voltage of the field-effect ultraviolet detector according to the gate voltage control signal. The first terminal of the signal amplifier is connected to the drain of the field-effect ultraviolet detector, and the second terminal of the signal amplifier is connected to the second terminal of the control unit. The signal amplifier is used to amplify the electrical signal output from the drain of the field-effect ultraviolet detector and transmit it to the control unit. The third terminal of the control unit is connected to the turbidity calculation module. The turbidity calculation module is specifically used to convert the electrical signal into the amount of light transmitted through the transmitted light, and to calculate the turbidity of the water body to be tested based on the amount of light transmitted through the transmitted light and the amount of light emitted by the ultraviolet optical module.

[0011] Optionally, the environmental changes of the water body to be detected include changes in the water temperature and changes in ambient humidity. The control unit is specifically used to determine the corresponding gate voltage based on the current changes in water temperature and ambient humidity of the water body to be detected, and to generate the corresponding gate voltage control signal; wherein different changes in water temperature and ambient humidity correspond to different gate voltages.

[0012] Optionally, the control unit is connected to the ultraviolet optical module, and the control unit is used to control the wavelength of the ultraviolet light emitted by the ultraviolet optical module and the initial gate voltage of the field-effect ultraviolet detector according to the current detection mode.

[0013] Optionally, the ultraviolet optical module includes a light source, a collimating lens, and a filter; The light source, the collimating lens, and the filter are all positioned directly opposite the first optical window. The collimating lens is located between the light source and the filter. The light source emits ultraviolet light to the collimating lens and the filter, which then transmits the light to the water body to be tested.

[0014] Optionally, the wavelength of the ultraviolet light emitted by the ultraviolet optical module includes 200nm-300nm.

[0015] Optionally, the water quality analyzer also includes a display module, which is connected to the turbidity calculation module. The display module is used to acquire the turbidity of the water body to be tested in real time, and to display and store the turbidity of the water body to be tested in real time.

[0016] This invention provides a water quality analyzer, which includes a detection pool body, an ultraviolet optical module, a signal detection and processing module, and a turbidity calculation module. The detection pool body is provided with a first optical window and a second optical window for light path penetration, which are arranged opposite to each other. The detection pool body is used to contain the water body to be tested. The ultraviolet optical module is located on the side of the detection pool body near the first optical window, and the light emission direction of the ultraviolet optical module is arranged opposite to the first optical window. The ultraviolet optical module is used to emit ultraviolet light to the water body to be tested so as to detect pollutants in the water body by ultraviolet light. The signal detection and processing module is located on the side of the detection pool body near the second optical window. The photosensitive side of the signal detection and processing module is directly opposite the second optical window. This module acquires the electrical signal of the transmitted light through the water body according to a preset detection sensitivity and sends it to the turbidity calculation module. The signal detection and processing module also adjusts the preset detection sensitivity according to changes in the environment of the water body, enabling different preset detection sensitivities in different environments. This achieves low-power operation and high-precision signal capture, improving environmental adaptability and operational stability, and flexibly adapting to diverse on-site monitoring scenarios. The turbidity calculation module is communicatively connected to the signal detection and processing module. It acquires the electrical signal of the transmitted light and determines the turbidity of the water body based on this signal, thus achieving water quality detection. Furthermore, the water quality analyzer of this invention has a simple circuit design architecture, which can reduce equipment manufacturing costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a water quality analyzer provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of another water quality analyzer provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the ultraviolet optical module provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of another water quality analyzer provided in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0019] In ultraviolet absorption water quality detection equipment, the detection devices mostly adopt photodiode PN junctions or metal-semiconductor-metal (MSM) structures. However, these devices exhibit several technical limitations in practical applications: First, their power consumption is relatively high and their dark current is large, making them unsuitable for long-term monitoring in remote water sources and aquaculture areas where continuous power supply is unavailable. Second, their light signal capture sensitivity is insufficient, resulting in a delayed response to subtle changes in light signals caused by low concentrations of pollutants in the water, thus limiting detection accuracy. Third, their low signal output amplitude necessitates complex filtering and multi-stage amplification circuits, significantly increasing equipment design costs. Fourth, the electrical parameters of the devices are easily affected by fluctuations in ambient temperature and humidity, requiring high-precision temperature compensation modules, moisture-proof protection structures, and multi-dimensional signal calibration circuits. This not only increases the instrument's size but also reduces its operational reliability in complex environments, making it difficult to flexibly adapt to diverse on-site monitoring scenarios. Therefore, overcoming the performance bottlenecks of traditional detection devices and developing a water quality analysis device that combines low power consumption, high sensitivity, and a simplified structure has become a pressing technical challenge in this field.

[0020] This invention provides a water quality analyzer to solve the above-mentioned technical problems. Figure 1 This is a schematic diagram of the structure of a water quality analyzer provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the water quality analyzer includes a detection tank body 110, an ultraviolet optical module 120, a signal detection and processing module 130, and a turbidity calculation module 140.

[0021] The detection pool body 110 is provided with a first optical window A1 and a second optical window A2 for light path penetration. The first optical window A1 and the second optical window A2 are arranged opposite each other. The detection pool body 110 is used to contain the water body to be detected.

[0022] The ultraviolet optical module 120 is located on the side of the detection pool body 110 near the first optical window A1, and the light emission direction of the ultraviolet optical module 120 is directly opposite to the first optical window A1. The ultraviolet optical module 120 is used to emit ultraviolet light to the water body to be detected.

[0023] The signal detection and processing module 130 is located on the side of the detection pool body 110 near the second optical window A2. The photosensitive side of the signal detection and processing module 130 is directly opposite the second optical window A2. The signal detection and processing module 130 is used to acquire the electrical signal of the transmitted light through the water body to be detected according to the preset detection sensitivity and send it to the turbidity calculation module 140. The signal detection and processing module 130 is also used to adjust the preset detection sensitivity according to the environmental changes of the water body to be detected.

[0024] The turbidity calculation module 140 is communicatively connected to the signal detection and processing module 130. The turbidity calculation module 140 is used to acquire the electrical signal of the transmitted light and determine the turbidity of the water body to be tested based on the electrical signal of the transmitted light.

[0025] The detection pool body 110 can be formed of high-transmittance quartz material. The side walls of the detection pool body 110 can be respectively provided with inlet and outlet ports, allowing the water to be tested to flow through the detection pool via natural flow or power-driven methods, achieving in-situ, non-retention detection. The detection pool body 110 has a first optical window A1 and a second optical window A2 on both sides for light path penetration. The first optical window A1 and the second optical window A2 are positioned opposite each other to ensure light path transparency.

[0026] Specifically, the ultraviolet optical module 120 is located on the side of the detection cell body 110 near the first optical window A1, and the signal detection and processing module 130 is located on the side of the detection cell body 110 near the second optical window A2, with the photosensitive side of the signal detection and processing module 130 facing the second optical window A2. During water quality testing, the water to be tested flows into the main body of the testing pool 110 through the inlet. It maintains a stable flow state as it flows through the first optical window A1 and the second optical window A2. The ultraviolet optical module 120 can emit a broad spectrum of ultraviolet light to the water to be tested and penetrate the water. The light emitted by the ultraviolet optical module 120 passes through the first optical window A1, the water to be tested, and the second optical window A2, and is then received by the photosensitive side of the signal detection and processing module 130. The signal detection and processing module 130 acquires the electrical signal of the transmitted light through the water to be tested according to the preset detection sensitivity, and uses the amplification gain characteristics of its own transistor to complete the preliminary amplification of the photogenerated electrical signal. The turbidity calculation module 140 can acquire the electrical signal of the transmitted light and, based on the Lambert-Beer law, calculate the concentration of pollutants in the water based on the electrical signal of the transmitted light, thereby determining the turbidity of the water to be tested.

[0027] Furthermore, the preset detection sensitivity can be the sensitivity of the signal detection and processing module 130 in acquiring the electrical signal of the transmitted light through the water body to be detected. For example, when the intensity of the transmitted light through the water body to be detected fluctuates frequently, a lower preset detection sensitivity can be set to stabilize the signal detected by the signal detection and processing module 130, thereby reducing operating power consumption. When the intensity of the transmitted light through the water body to be detected fluctuates less, a higher preset detection sensitivity can be set to increase the accuracy of the signal detected by the signal detection and processing module 130, thereby reducing operating power consumption and achieving low-power operation and high-precision signal capture.

[0028] The environmental changes of the water body to be tested can be reflected by the real-time fluctuation of the turbidity of the water body. When the ambient temperature and humidity fluctuate or the turbidity of the water body changes abruptly, that is, when the real-time fluctuation of the turbidity of the water body to be tested determined by the turbidity calculation module 140 is large, the signal detection and processing module 130 can adjust the preset detection sensitivity to stabilize the signal detected by the signal detection and processing module 130, thereby reducing the operating power consumption, ensuring the stability and accuracy of the detection data, improving environmental adaptability and operational stability, and flexibly adapting to diverse on-site monitoring scenarios.

[0029] It should be noted that the signal detection and processing module 130 of the water quality analyzer provided in this embodiment of the invention can adopt a field-effect ultraviolet detector. By utilizing the core characteristics of low power consumption and high sensitivity of field-effect devices, it can accurately adapt to the long-term monitoring and real-time detection needs of multiple scenarios such as drinking water source monitoring, industrial wastewater discharge monitoring, and aquaculture water quality control.

[0030] This invention provides a water quality analyzer, which includes a detection pool body, an ultraviolet optical module, a signal detection and processing module, and a turbidity calculation module. The detection pool body is provided with a first optical window and a second optical window for light path penetration, which are arranged opposite to each other. The detection pool body is used to contain the water body to be tested. The ultraviolet optical module is located on the side of the detection pool body close to the first optical window, and the light emission direction of the ultraviolet optical module is arranged opposite to the first optical window. The ultraviolet optical module is used to emit ultraviolet light to the water body to be tested so as to detect pollutants in the water body by ultraviolet light. The signal detection and processing module is located on the side of the detection pool body near the second optical window. The photosensitive side of the signal detection and processing module is directly opposite the second optical window. This module acquires the electrical signal of the transmitted light through the water body according to a preset detection sensitivity and sends it to the turbidity calculation module. The signal detection and processing module also adjusts the preset detection sensitivity according to changes in the environment of the water body, enabling different preset detection sensitivities in different environments. This achieves low-power operation and high-precision signal capture, improving environmental adaptability and operational stability, and flexibly adapting to diverse on-site monitoring scenarios. The turbidity calculation module is communicatively connected to the signal detection and processing module. It acquires the electrical signal of the transmitted light and determines the turbidity of the water body based on this signal, thus achieving water quality detection. Furthermore, the water quality analyzer of this invention has a simple circuit design architecture, which can reduce equipment manufacturing costs.

[0031] Figure 2 This is a schematic diagram of another water quality analyzer provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the signal detection and processing module 130 includes a field-effect ultraviolet detector 131 and a gate voltage regulation unit 132.

[0032] The photosensitive surface of the field-effect ultraviolet detector 131 serves as the photosensitive side of the signal detection and processing module 130, and the gate voltage adjustment unit 132 is connected to the gate of the field-effect ultraviolet detector 131.

[0033] The gate voltage adjustment unit 132 is used to control the gate voltage of the field-effect ultraviolet detector 131 to control the preset detection sensitivity; the field-effect ultraviolet detector 131 is used to acquire the transmitted light through the water body to be detected, convert the transmitted light into an electrical signal, and amplify the electrical signal.

[0034] The field-effect ultraviolet detector 131 can be a field-effect ultraviolet photodiode, a photodetector based on a field-effect transistor structure. It detects ultraviolet signals by modulating the channel conductivity using photogenerated carriers. Compared to traditional photodiodes, the field-effect ultraviolet detector 131 offers advantages such as high gain, low noise, and low power consumption, effectively improving the sensitivity and signal-to-noise ratio of ultraviolet detection. Its working principle involves using ultraviolet light to irradiate the semiconductor material of the field-effect ultraviolet detector 131 to generate electron-hole pairs. These photogenerated carriers alter the carrier concentration in the channel region, thereby modulating the source-drain current and converting the optical signal into an electrical signal. This structure is particularly suitable for detecting weak ultraviolet signals and has broad application prospects in environmental monitoring, water quality analysis, and flame detection. In this embodiment, the field-effect ultraviolet detector 131 is used as the core device of the water quality analyzer, which can improve the accuracy of water quality analysis, achieve high-precision signal capture, and, thanks to its transistor amplification gain characteristics, directly amplify the electrical signal formed by the photogenerated carriers.

[0035] The gate voltage of the field-effect ultraviolet detector 131 is a key parameter controlling the operating state of the device. Adjusting the gate voltage changes the channel carrier concentration, thus affecting the sensitivity and response characteristics of the field-effect ultraviolet detector 131. At zero or negative gate voltage, the device is in a depletion state with extremely low dark current, suitable for detecting weak light signals. Applying a positive gate voltage allows carriers to accumulate in the channel, enhancing photocurrent gain and improving detection sensitivity. Optimizing the gate voltage requires balancing sensitivity, response speed, dark current, and noise level, and the optimal operating point is typically determined through experimental testing. Furthermore, the stability of the gate voltage directly affects the long-term reliability of the detector; related technologies usually require temperature compensation circuitry to suppress drift caused by changes in ambient temperature. In this embodiment, the gate voltage adjustment unit 132 can adjust and control the gate voltage of the field-effect ultraviolet detector 131 in real time to suppress drift caused by changes in ambient temperature. Optionally, the preset detection sensitivity is the gate voltage of the field-effect ultraviolet detector 131; by controlling the gate voltage of the field-effect ultraviolet detector 131, the preset detection sensitivity is controlled.

[0036] Specifically, the photosensitive surface of the field-effect ultraviolet detector 131 serves as the photosensitive side of the signal detection and processing module 130, acquiring the transmitted light from the water body to be detected. Ultraviolet light irradiates the semiconductor material of the field-effect ultraviolet detector 131, generating electron-hole pairs. These photogenerated carriers alter the carrier concentration in the channel region, thereby modulating the source-drain current and converting the optical signal into an electrical signal. Utilizing the transistor amplification gain characteristics of the field-effect ultraviolet detector 131, the electrical signal formed by the photogenerated carriers can be directly amplified. The gate voltage adjustment unit 132 is connected to the gate of the field-effect ultraviolet detector 131. The gate voltage adjustment unit 132 can control the gate voltage of the field-effect ultraviolet detector 131 by applying voltage, thereby controlling the preset detection sensitivity and achieving low-power operation and high-precision signal capture. For example, when the ambient temperature and humidity fluctuate or the turbidity of the water changes abruptly, the gate voltage adjustment unit 132 is triggered to fine-tune the gate voltage, simultaneously achieving temperature compensation and signal calibration functions, thus ensuring the stability and accuracy of the detection data.

[0037] Optionally, the field-effect ultraviolet detector 131 includes an n-channel metal-semiconductor field-effect transistor, and the photosensitive surface of the field-effect ultraviolet detector 131 includes silicon carbide or gallium nitride.

[0038] The field-effect ultraviolet detector 131 uses wide-bandgap semiconductors such as silicon carbide and gallium nitride as the photosensitive surface of the core photosensitive layer, achieving efficient ultraviolet light detection without the need for a high bias voltage, thereby reducing power consumption. The gate voltage adjustment unit 132, through gate voltage fine-tuning, can compensate for the impact of ambient temperature fluctuations on device parameters. It can also adjust the gate voltage in real time to stabilize the output signal of the field-effect ultraviolet detector 131 when sudden changes in water turbidity cause drastic fluctuations in the light signal, completely eliminating the need for additional signal calibration circuits in traditional equipment. This embodiment of the invention utilizes the unique gate voltage regulation advantage of the field-effect structure in the field-effect ultraviolet detector 131 to achieve low-power operation and high-precision signal capture during the detection process, while significantly simplifying the circuit design architecture, reducing equipment manufacturing costs, and improving environmental adaptability and operational stability.

[0039] Optionally, the dark current of the field-effect ultraviolet detector 131 is ≤1nA, and the transconductance of the field-effect ultraviolet detector 131 is ≥50mS / mm, so that the field-effect ultraviolet detector 131 has the ability to initially amplify the photogenerated signal.

[0040] In some embodiments of the present invention, the signal detection and processing module 130 further includes a control unit 133 and a signal amplifier 134.

[0041] The first terminal of the control unit 133 is connected to the gate voltage adjustment unit 132. The control unit 133 is used to generate a corresponding gate voltage control signal according to the environmental changes of the water body to be detected, and send it to the gate voltage adjustment unit 132. The gate voltage adjustment unit 132 is specifically used to control the gate voltage of the field effect ultraviolet detector 131 according to the gate voltage control signal.

[0042] The control unit 133 can be a microcontroller, specifically an STM32 series microcontroller. Environmental changes affecting the water body include variations in water temperature and humidity. Different temperature and humidity changes correspond to different gate voltages. These changes can be directly measured by sensors, allowing the control unit 133 to determine the appropriate gate voltage and generate a corresponding gate voltage control signal. This enables the gate voltage adjustment unit 132 to control the gate voltage of the field-effect ultraviolet detector 131 in real-time, achieving low-power operation and high-precision signal capture for the water quality analyzer.

[0043] In addition, environmental changes in the water body to be detected may also include changes in the turbidity of the water body to be detected. When rainfall causes a short-term sudden change in the turbidity of the water body to be detected, that is, when the real-time fluctuation of the turbidity of the water body to be detected determined by the turbidity calculation module 140 is large, the control unit 133 can determine the corresponding gate voltage by real-time monitoring of the turbidity fluctuation of the water body to be detected, and generate the corresponding gate voltage control signal, thereby ensuring the stability and accuracy of the detection data of the field effect ultraviolet detector 131, so as to improve environmental adaptability and operational stability, and can flexibly adapt to diverse on-site monitoring scenarios.

[0044] The linkage control mechanism established between the microcontroller and the gate voltage adjustment unit 132 can not only compensate for the influence of ambient temperature fluctuations on device parameters through gate voltage fine adjustment, but also adjust the gate voltage in real time to stabilize the output signal when the light signal fluctuates drastically due to sudden changes in water turbidity, thus completely eliminating the need for additional signal calibration circuits in traditional equipment.

[0045] The gate voltage adjustment unit 132 can output an adjustable voltage of 0-5V with a voltage control accuracy of 0.01V, thereby achieving precise control of the gate voltage of the field-effect ultraviolet detector 131 and thus achieving precise control of the working state of the field-effect ultraviolet detector 131.

[0046] The first terminal of the signal amplifier 134 is connected to the drain of the field-effect ultraviolet detector 131, and the second terminal of the signal amplifier 134 is connected to the second terminal of the control unit 133. The signal amplifier 134 is used to amplify the electrical signal output from the drain of the field-effect ultraviolet detector 131 and transmit it to the control unit 133.

[0047] The third terminal of the control unit 133 is connected to the turbidity calculation module 140. The turbidity calculation module 140 is specifically used to convert electrical signals into the amount of transmitted light, and calculate the turbidity of the water body to be tested based on the amount of transmitted light and the amount of ultraviolet light emitted by the ultraviolet optical module 120.

[0048] Specifically, the signal amplifier 134 amplifies the electrical signal output from the drain of the field-effect ultraviolet detector 131 and transmits it to the control unit 133, thereby further amplifying the detection signal and ensuring that the electrical signal can be recognized by the turbidity calculation module 140. The turbidity calculation module 140 converts the electrical signal into the amount of transmitted light, and calculates the turbidity of the water body to be detected based on the amount of transmitted light and the amount of ultraviolet light emitted by the ultraviolet optical module 120. For example, it can use the Lambert-Beer law, the mathematical expression of which is: A=lg( )=εcL; Where A is the absorbance of the water body to be tested; I0 is the light intensity of the ultraviolet light emitted by the ultraviolet optical module 120, which can be represented by the amount of ultraviolet light emitted by the ultraviolet optical module 120; I is the transmitted light intensity, which can be represented by the amount of transmitted light; ε is the molar absorptivity, which is a constant related to the type of pollutant and the wavelength of light; c is the concentration of the pollutant, which can be equivalent to the turbidity of the water body to be tested; L is the optical path, which is the distance that the ultraviolet light travels through the water body to be tested. In the water quality analyzer provided in this embodiment of the invention, it is the distance between the first optical window A1 and the second optical window A2, which is a fixed value. The concentration c of the pollutant in the water body to be tested can be calculated as the turbidity of the water body to be tested using the Lambert-Beer law, thus realizing the real-time detection of the turbidity of the water body to be tested.

[0049] The electrical signal initially amplified by the field-effect ultraviolet detector 131 can be fed into the signal amplifier 134 for amplitude optimization before finally being transmitted to the microcontroller for data processing. By utilizing the built-in amplification function of the field-effect ultraviolet detector 131, the additional filtering circuits and complex multi-stage amplification modules required by traditional equipment are eliminated, reducing hardware costs. Simultaneously, the number of circuit failure points is reduced, improving equipment reliability and lowering subsequent maintenance costs.

[0050] In some embodiments of the present invention, the control unit 133 is connected to the ultraviolet optical module 120, and the control unit 133 is used to control the wavelength of the ultraviolet light emitted by the ultraviolet optical module 120 and the initial gate voltage of the field-effect ultraviolet detector 131 according to the current detection mode.

[0051] Specifically, the ultraviolet light emitted by the ultraviolet optical module 120 can cover the wavelength range of 200nm-300nm. The wavelength of the ultraviolet light emitted by the ultraviolet optical module 120 can be switched using a narrowband filter. For example, when detecting chemical oxygen demand (COD), the wavelength corresponds to 254nm. Organic matter in water (such as humic acid and aromatic compounds) has a very strong absorption peak near 254nm, as do nitrates (NO3). - There is a strong absorption peak near the 220nm wavelength. For water bodies with different pollutants, different wavelengths of ultraviolet light can be selected for detection. The water quality analyzer has multiple detection modes, each targeting a specific pollutant, and each mode has a corresponding wavelength of ultraviolet light emitted by the ultraviolet optical module 120. Different detection modes can also be used to detect pollutants in water bodies under different outdoor environments. For example, in rainy, snowy, or hot weather, the water temperature may be low or high, or the turbidity may change abruptly due to rainfall. Different detection modes can be set for different outdoor environments, and the initial gate voltage of the corresponding field-effect ultraviolet detector 131 can be set accordingly. The control unit 133 can then control the wavelength of the ultraviolet light emitted by the ultraviolet optical module 120 and the initial gate voltage of the field-effect ultraviolet detector 131 based on the current detection mode, thereby improving the accuracy of the detection structure.

[0052] Figure 3 This is a schematic diagram of the structure of the ultraviolet optical module provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the ultraviolet optical module 120 includes a light source 121, a collimating lens 122, and a filter 123.

[0053] The light source 121, collimating lens 122 and filter 123 are all positioned directly opposite the first optical window A1. The collimating lens 122 is located between the light source 121 and the filter 123. The light source 121 is used to emit ultraviolet light to the collimating lens 122 and the filter 123, and the light is transmitted to the water body to be detected through the collimating lens 122 and the filter 123.

[0054] Different pollutants absorb light differently at different wavelengths. This means that the intensity of ultraviolet light received by the field-effect ultraviolet detector 131 after passing through the water body to be tested varies depending on the type and concentration of the pollutant. Therefore, the ultraviolet optical module 120 can emit ultraviolet light of different wavelengths for different pollutants, allowing the target wavelength to be switched according to the detection requirements. The filter 123 can be a narrowband filter, allowing only ultraviolet light of the corresponding wavelength to pass through, thus ensuring that the ultraviolet optical module 120 emits only ultraviolet light of the corresponding wavelength. The collimating lens 122 can calibrate the divergent ultraviolet light into a parallel beam, ensuring that the ultraviolet optical module 120 outputs monochromatic ultraviolet light that vertically illuminates the water body to be tested.

[0055] The water quality analyzer of this invention exhibits strong environmental adaptability, specifically because the parameters of the field-effect ultraviolet detector 131 are less affected by temperature and humidity, eliminating the need for additional moisture-proof protection circuitry. The dynamic adjustment mechanism of the grid voltage of the field-effect ultraviolet detector 131 can quickly adapt to sudden changes in water turbidity, enabling the device to operate stably in harsh environments with temperatures ranging from -10℃ to 45℃ and humidity ≤90%, making it suitable for various indoor and outdoor testing scenarios. The high sensitivity and precision of the water quality analyzer of this invention are specifically manifested in the following ways: the amplification gain characteristics and high transconductance of the field-effect ultraviolet detector 131 significantly enhance its ability to capture weak light signals, resulting in a substantial increase in detection sensitivity compared to traditional devices. Combined with the grid voltage dynamic calibration mechanism, the detection error can be stably controlled within ±3%, enabling accurate identification of subtle changes caused by low-concentration pollutants in the water. The water quality analyzer of this invention features simplified circuitry and low cost, specifically because the built-in signal amplification function of the field-effect ultraviolet detector 131 eliminates the need for additional filtering circuits, multi-stage amplification modules, and complex calibration circuits required by traditional equipment, thus reducing hardware costs. At the same time, the number of circuit failure points is reduced, improving the reliability of equipment operation and reducing subsequent maintenance costs.

[0056] Figure 4 This is a schematic diagram of the structure of another water quality analyzer provided in an embodiment of the present invention, as shown below. Figure 4 As shown, in some embodiments of the present invention, the water quality analyzer further includes a display module 150, which is connected to the turbidity calculation module 140. The display module 150 is used to acquire the turbidity of the water body to be tested in real time, and to display and store the turbidity of the water body to be tested in real time.

[0057] Specifically, the display module 150 may include a touch screen and a dual-mode power module. The touch screen can acquire, display, and store the turbidity of the water body under test in real time, thereby realizing the functions of inputting detection parameters, displaying real-time data, and querying historical records. The dual-mode power module supports both mains power supply and lithium battery power supply modes to ensure stable power supply for the device in different scenarios. The display module 150 can also be connected to the control unit 133 to establish a bidirectional communication link between the display module 150 and the control unit 133.

[0058] In this embodiment of the invention, when the provided water quality analyzer is applied to a long-term drinking water source monitoring scenario, the analyzer is fixedly installed at the monitoring point of the drinking water source and uses a lithium battery power supply to start the continuous monitoring program. The "COD Continuous Monitoring" mode is set via the display module 150. The control unit 133 automatically matches the 254nm target wavelength and outputs a 2.5V gate voltage to the field-effect ultraviolet detector 131. At this time, the device's power consumption is controlled within 5mW. During monitoring, when the water temperature rises from 10℃ to 40℃, or when rainfall causes a short-term sudden change in water turbidity, the control unit 133 automatically fine-tunes the gate voltage to the 2.3V-2.7V range by monitoring the output signal fluctuations in real time, ensuring stable detection signals. The control unit 133 of the water quality analyzer can automatically record COD concentration data once per hour, with all detection data errors controlled within ±2%, meeting the accuracy and battery life requirements for long-term drinking water source monitoring.

[0059] In this embodiment of the invention, the provided water quality analyzer is integrated into the online monitoring system of the industrial wastewater discharge outlet when applied to a real-time monitoring scenario. It is connected to mains power and the "nitrate detection" mode is selected. The control unit 133 controls the ultraviolet optical module 120 to automatically switch to the 220nm detection wavelength, outputting a 1.8V gate voltage to drive the field-effect ultraviolet detector 131. Thanks to the signal amplification function of the field-effect ultraviolet detector 131, the complete detection cycle from light signal reception to concentration data output takes only 1 second, meeting the rapid response requirements of industrial scenarios. When fluctuations in the wastewater treatment process cause sudden changes in turbidity, resulting in drastic fluctuations in the transmitted light signal, the gate voltage adjustment unit 132 automatically adjusts by 0.5V under the control of the control unit 133, instantly stabilizing the output signal and ensuring the continuity and accuracy of nitrate emission concentration data, providing reliable data support for environmental compliance emissions.

[0060] This invention provides a water quality analyzer designed to address the technical problems of complex circuit design, high power consumption, and low detection accuracy in existing ultraviolet absorption water quality detection equipment. The core innovation of this water quality analyzer lies in its use of a field-effect ultraviolet detector, leveraging its gate voltage regulation advantage to achieve low bias voltage operation, significantly reducing device power consumption compared to traditional equipment. Furthermore, the detector's built-in amplification gain characteristics eliminate the need for additional filtering and amplification circuits. Through the linkage between the control unit and the gate voltage adjustment unit, temperature compensation and turbidity fluctuation adaptation functions are simultaneously achieved. The water quality analyzer of this invention features a simplified structure, low manufacturing cost, and flexible adaptability to both long-term monitoring and real-time detection scenarios, demonstrating significant practical value in the field of water quality monitoring.

[0061] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A water quality analyzer, characterized in that, It includes the main body of the detection cell, the ultraviolet optical module, the signal detection and processing module, and the turbidity calculation module; The detection pool body is provided with a first optical window and a second optical window for light path penetration. The first optical window and the second optical window are arranged facing each other. The detection pool body is used to contain the water body to be detected. The ultraviolet optical module is located on the side of the detection pool body close to the first optical window, and the light emission direction of the ultraviolet optical module is directly opposite to the first optical window. The ultraviolet optical module is used to emit ultraviolet light to the water body to be detected. The signal detection and processing module is located on the side of the detection pool body close to the second optical window. The photosensitive side of the signal detection and processing module is directly opposite the second optical window. The signal detection and processing module is used to acquire the electrical signal of the transmitted light through the water body to be detected according to the preset detection sensitivity and send it to the turbidity calculation module. The signal detection and processing module is also used to adjust the preset detection sensitivity according to the environmental changes of the water body to be detected. The turbidity calculation module is communicatively connected to the signal detection and processing module. The turbidity calculation module is used to acquire the electrical signal of the transmitted light and determine the turbidity of the water body to be detected based on the electrical signal of the transmitted light.

2. The water quality analyzer according to claim 1, characterized in that, The signal detection and processing module includes a field-effect ultraviolet detector and a gate voltage regulation unit; The photosensitive surface of the field-effect ultraviolet detector serves as the photosensitive side of the signal detection and processing module, and the gate voltage adjustment unit is connected to the gate of the field-effect ultraviolet detector. The gate voltage adjustment unit is used to control the gate voltage of the field-effect ultraviolet detector to control the preset detection sensitivity; the field-effect ultraviolet detector is used to acquire the transmitted light through the water body to be detected, convert the transmitted light into an electrical signal, and amplify the electrical signal.

3. The water quality analyzer according to claim 2, characterized in that, The field-effect ultraviolet detector includes an n-channel metal-semiconductor field-effect transistor, and the photosensitive surface of the field-effect ultraviolet detector includes silicon carbide or gallium nitride.

4. The water quality analyzer according to claim 2, characterized in that, The dark current of the field-effect ultraviolet detector is ≤1nA, and the transconductance of the field-effect ultraviolet detector is ≥50mS / mm.

5. The water quality analyzer according to claim 2, characterized in that, The signal detection and processing module also includes a control unit and a signal amplifier; The first end of the control unit is connected to the gate voltage adjustment unit. The control unit is used to generate a corresponding gate voltage control signal according to the environmental changes of the water body to be detected, and send it to the gate voltage adjustment unit. The gate voltage adjustment unit is specifically used to control the gate voltage of the field-effect ultraviolet detector according to the gate voltage control signal. The first terminal of the signal amplifier is connected to the drain of the field-effect ultraviolet detector, and the second terminal of the signal amplifier is connected to the second terminal of the control unit. The signal amplifier is used to amplify the electrical signal output from the drain of the field-effect ultraviolet detector and transmit it to the control unit. The third terminal of the control unit is connected to the turbidity calculation module. The turbidity calculation module is specifically used to convert the electrical signal into the amount of light transmitted through the transmitted light, and to calculate the turbidity of the water body to be tested based on the amount of light transmitted through the transmitted light and the amount of light emitted by the ultraviolet optical module.

6. The water quality analyzer according to claim 5, characterized in that, The environmental changes of the water body to be tested include changes in the water temperature and changes in ambient humidity. The control unit is specifically used to determine the corresponding gate voltage based on the current changes in water temperature and ambient humidity of the water body to be detected, and to generate the corresponding gate voltage control signal; wherein different changes in water temperature and ambient humidity correspond to different gate voltages.

7. The water quality analyzer according to claim 5, characterized in that, The control unit is connected to the ultraviolet optical module, and the control unit is used to control the wavelength of the ultraviolet light emitted by the ultraviolet optical module and the initial gate voltage of the field-effect ultraviolet detector according to the current detection mode.

8. The water quality analyzer according to claim 1, characterized in that, The ultraviolet optical module includes a light source, a collimating lens, and a filter; The light source, the collimating lens, and the filter are all positioned directly opposite the first optical window. The collimating lens is located between the light source and the filter. The light source emits ultraviolet light to the collimating lens and the filter, which then transmits the light to the water body to be tested.

9. The water quality analyzer according to claim 1, characterized in that, The ultraviolet light emitted by the ultraviolet optical module has a wavelength of 200nm-300nm.

10. The water quality analyzer according to claim 1, characterized in that, It also includes a display module, which is connected to the turbidity calculation module. The display module is used to acquire the turbidity of the water body to be tested in real time, and to display and store the turbidity of the water body to be tested in real time.

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