An adjustable range dual-light-source water quality COD detection sensor

Abstract

The present invention discloses an adjustable-range dual-light-source water quality COD detection sensor, which includes a housing, a light source part, an absorption chamber part, and a photoelectric detection part. The light source part adopts a dual light source, including irradiation light and reference light. A sample inlet hole and a sample inlet hole cover are provided on the housing corresponding to the position of the absorption chamber. The light source part and the absorption chamber part are separated by a transparent sliding partition. The light source is fixed on the transparent sliding partition, and the transparent sliding partition is controlled by a sliding partition controller. The absorption chamber part and the photoelectric detection part are separated by a transparent fixed partition. The present invention proposes to change the optical path from the light source to the photoelectric detector, thereby changing the range and measurement accuracy. At the same time, by adding reference light, the interference of factors such as turbidity, water color, and temperature on the measurement results is reduced, the water temperature is detected in real time, and temperature compensation is performed to improve the accuracy.

Description

Technical Field

[0001] The present invention relates to an optical detection sensor, and particularly to an intelligent sensor for detecting the COD parameter in water, belonging to the technical field of water quality detection. Background Art

[0002] In recent years, with the increasing aggravation of water resource pollution, people have gradually started to pay attention to the work of water quality detection. According to the water quality detection technical requirements of our country, COD is one of the most important parameters for measuring water quality, and COD reflects the degree of pollution of water quality by redox substances. The commonly used detection methods for COD mainly include chemical method, electrochemical method, optical method and biological method. However, the chemical method, electrochemical method and biological method generally have problems such as consuming reagents, being prone to causing secondary pollution, having expensive detection instruments, and relatively high detection costs. Due to the advantages of the optical method equipment such as not consuming reagents and not being prone to causing secondary pollution, the research and application of optical water quality analysis methods and detection equipment have received extensive attention in recent years and tend to be miniaturized and portable.

[0003] According to the Lambert-Beer law, it means that when a beam of parallel monochromatic light passes through a homogeneous and non-scattering dilute solution, the absorption degree of the solution to light is proportional to the product of the solution concentration and the liquid layer. When the solution concentration remains unchanged, by changing the thickness of the liquid layer, the measurement range and accuracy of the optical sensor are changed. The thinner the liquid layer, the larger the measurement range and the lower the measurement accuracy. The thicker and longer the liquid layer, the smaller the measurement range and the higher the measurement accuracy. Most organic substances in water have absorption characteristics in the UV region. By irradiating the water layer with a specific wavelength of UV, part of the UV is absorbed by the organic substances in the water. When the thickness of the liquid layer remains unchanged, by detecting the difference between the absorbed UV and the pre-absorbed UV, the concentration of organic substances in the water can be measured. Based on the above principle, the present invention adjusts the measurement range and measurement accuracy of the optical sensor by changing the thickness of the liquid layer, and the liquid layer thickness is the length of the light absorption chamber of the sensor. The intelligent sensor for detecting the COD parameter of water with adjustable range and dual light sources of the present invention, compared with the single light source sensor, excludes the interference of factors such as water turbidity and water color on the measurement result by adding a reference light source; compared with the currently commercially available COD detection reagents or instruments, it has the advantages of no secondary pollution of chemical reagents, small equipment volume, adjustable range, and low operation difficulty. Summary of the Invention

[0004] The object of the present invention is to provide an adjustable-range dual-light-source water-quality COD detection sensor, which provides a convenient and lightweight sensor for detecting the COD concentration of water-quality parameters. This sensor can be applied to the detection of water-quality COD concentration. Its advantage lies in using dual light sources as the light source, which can reduce the interference of factors such as turbidity, water color, and temperature on the measurement results, and can detect the water temperature in real time and perform temperature compensation. By estimating the COD concentration in the water sample, the measurement range and measurement accuracy of a dual-light-source COD sensor are adjusted by adjusting the axial distance of the liquid chamber. It has high stability, high measurement accuracy, simple structure, small size, light weight, convenient use, reduces various cumbersome steps of water-quality parameters, and reduces secondary pollution caused by chemical reagents, etc.

[0005] The technical solution of the present invention is as follows:

[0006] An adjustable-range dual-light-source water-quality COD detection sensor includes a housing, a light-source part, an absorption chamber part, and a photoelectric detection part. The light-source part uses dual light sources, including irradiation light and reference light. A sampling hole and a sampling-hole cover are provided on the housing corresponding to the position of the absorption chamber. The sampling hole is used for the entry of the water sample to be measured to fill the entire absorption chamber, and there is a sampling-hole cover on the sampling hole to prevent the leakage of the sample to be measured. The light-source part and the absorption chamber part are separated by a transparent sliding partition. The light source is fixed on the transparent sliding partition, and the transparent sliding partition is controlled by a sliding partition controller. The absorption chamber part and the photoelectric detection part are separated by a transparent fixed partition.

[0007] The light source is fixed on the transparent sliding partition by quick-drying glue. The light source can move as the partition slides, so that the optical path also changes accordingly, adjusting the measurement range and measurement accuracy. The absorption chamber is the position where the organic matter in the liquid water sample absorbs part of the ultraviolet light during detection. By changing the transparent sliding partition to change the optical path, the method of changing the transparent sliding partition can be to control it by manually moving the transparent sliding partition controller.

[0008] More preferably, the reference light is blue light and the irradiation light is ultraviolet light. A thermometer is provided in the absorption chamber to be able to detect the water temperature in real time and perform temperature compensation to improve the accuracy.

[0009] More preferably, both the transparent sliding partition and the transparent fixed partition are transparent quartz glass plates.

[0010] More preferably, the photoelectric detection includes two filter plates, two detectors, and a circuit part; each light source, filter plate, and photoelectric detector are on the same horizontal line, and the optical path from each light source to the detector is the same.

[0011] More preferably, the detector includes two photodiodes, which are used to detect the blue-light source and ultraviolet-light source absorbed by the organic matter in the absorption chamber and convert the optical signal into an electrical signal.

[0012] Preferably, the circuit part includes an analog amplification module, a CPU processing module, a GPRS communication module, and a laser driver chip for voltage-regulated current, which are soldered on the circuit board. Meanwhile, the circuit board is externally connected with wires, data lines, and wires between various parts of the circuit. The main function of the CPU processor is to process the electrical signals amplified by the analog amplification module, convert them into displayable data, and store and transmit the processed data.

[0013] Preferably, for the laser driver chip for voltage-regulated current, pulse modulation is performed through a single-chip microcomputer to adjust the PWM duty cycle. The output pulse signal is transmitted to the driver chip to change the circuit voltage, thereby changing the circuit current, so that the light source can reach the required brightness.

[0014] Preferably, the exterior of the housing is a cylindrical housing. There is a flat platform inside the housing. The transparent sliding partition and the transparent fixed partition are both arranged on the platform, and the space formed by the platform and the housing is divided into a light source part, a light absorption chamber part, and a photoelectric detection part. On the diameter of the housing, the light source, the photodetector, and the circuit board are all on the flat platform, and the light source and the photodetector are in the same plane.

[0015] Preferably, the housing is provided with a wire groove that penetrates through the power supply part, the light absorption chamber part, and the photoelectric detection part for placing the circuit. The wire groove is sealed with a transparent cover on top to prevent water from entering the circuit.

[0016] Preferably, the analog amplification module is mainly composed of an amplification circuit formed by triodes, and its main function is to amplify the required electrical signals without distortion.

[0017] Beneficial effects: The present invention proposes to change the optical path from the light source to the photodetector, thereby changing the measurement range and measurement accuracy. At the same time, by adding a reference light, the interference of factors such as turbidity, water color, and temperature on the measurement result is reduced, and the water temperature is detected in real time, and temperature compensation is performed to improve the accuracy. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only the preferred embodiments of the present invention and do not limit the scope of the present invention. The drawings are not to scale (except as specified) and are intended to be used in conjunction with the description in the following detailed description.

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present invention;

[0020] The reference numerals in the figure are: 1 - flat stage, 2 - housing, 3 - blue light source, 4 - ultraviolet light source, 5 - transparent sliding partition controller, 6 - transparent sliding partition, 7 - sampling port, 8 - transparent fixed partition, 9 - photodetector, 10 - circuit board, 11 - CPU processor, 12 - laser driver chip for voltage regulating current, 13 - analog amplification module, 14 - GPRS communication module, 15 - wire groove. Detailed implementation manner

[0021] To better understand the technical content of the present invention, specific embodiments will be provided below in conjunction with the drawings in the present invention, and the present invention will be further described in conjunction with the drawings.

[0022] As Figure 1 shown, an adjustable range dual - light - source water - quality COD detection sensor mainly includes three parts: a light - source part, an absorption chamber part, and a photoelectric detection part. The light - source part and the absorption chamber part are separated by a transparent sliding partition 6. The light - source part mainly includes a blue light source 3 and an ultraviolet light source 4. The blue light source 3 and the ultraviolet light source 4 are fixed on the transparent sliding partition 6 by quick - drying glue. A transparent sliding partition controller 5 is fixed on the transparent sliding partition 6. By means of the sliding controller 5, the transparent sliding partition 6 and the light source are slid to control the thickness of the liquid layer. There is a liquid sampling port 7 on the housing 2. During detection, the sample liquid fills the entire liquid chamber. The photoelectric detection part and the absorption chamber part are separated by a transparent fixed partition 8. The photoelectric detection part is mainly composed of a filter, a photodiode, and an amplification circuit. The filter, the photodiode, the blue light source 3, and the ultraviolet light source 4 are all arranged on the flat stage 1. The light source, the filter, and the photodetector 9 are on the same horizontal line. The housing 2 is located outside the entire device for protecting the entire device. There is a sampling port 7 on the housing 2 for the entry of the water sample to be measured to fill the entire liquid chamber. At the same time, there is a wire groove 15 on the housing 2 that penetrates through the power supply part, the absorption chamber part, and the photoelectric detection part for placing the circuit, and a transparent cover is sealed on it.

[0023] The whole device detection process is as follows: Place the whole device in the water sample to be measured, so that the water sample enters the light absorption chamber from the sampling port 7 on the housing 2 and fills the whole light absorption chamber. Roughly estimate the COD concentration in the water sample, manually pull the sliding partition controller 5 to move the transparent sliding partition 6, drive the blue light source 3 and the ultraviolet light source 4 fixed to the transparent sliding partition 6 to move back and forth, while the position of the photodetector 9 is fixed. Control the length of the optical path by adjusting the light source, and then select the appropriate range and accuracy. After selecting the range, turn on the power supply, perform pulse modulation through the single-chip microcomputer, adjust the PWM duty cycle, and transmit the output pulse signal to the laser driver chip 12 to change the circuit voltage, thereby changing the circuit current and enabling the light source to reach the required brightness. At this time, the blue light and the ultraviolet light irradiate the water sample to be measured at the same time. The organic matter in the water sample absorbs part of the ultraviolet light. The higher the concentration of the organic matter in the water, the more ultraviolet light is absorbed. The reference light blue light is not absorbed by the organic matter in the water sample, but the turbidity of the water sample will affect the detection of light by the photodetector 9. The photodetectors 9 corresponding to the blue light source 3 and the ultraviolet light source 4 respectively detect the reference light blue light and the ultraviolet light passing through the water sample, convert the detected light signals into electrical signals, the electrical signals pass through the analog amplification module 13 to amplify the electrical signals, and transmit the amplified electrical signals to the CPU processor 11. The CPU processor 11 processes the electrical signals transmitted by the analog amplification module 13 into displayable a / d signals, and transmits the processed displayable signals to the display through the GPRS communication module 14.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still can modify the specific embodiments of the present invention or perform equivalent substitution on some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered by the scope of the technical solutions claimed in the present invention.

Claims

1. An adjustable range dual-light-source water quality COD detection sensor, characterized in that, It includes a housing, a light source part, an absorption chamber part, and a photoelectric detection part. The light source part uses a dual light source, including irradiation light and reference light. There are a sample inlet hole and a sample inlet hole cover corresponding to the position of the absorption chamber on the housing. The light source part and the absorption chamber part are separated by a transparent sliding partition. The light source is fixed on the transparent sliding partition, and the transparent sliding partition is controlled by a sliding partition controller. The absorption chamber part and the photoelectric detection part are separated by a transparent fixed partition.

2. The adjustable range dual-light-source water quality COD detection sensor according to claim 1, characterized in that The reference light is blue light, the irradiation light is ultraviolet light, and a thermometer is provided in the absorption chamber.

3. The adjustable-range dual-light-source water-quality COD detection sensor according to claim 1, wherein, Both the transparent sliding partition and the transparent fixed partition are transparent quartz glass plates.

4. The adjustable-range dual-light-source water-quality COD detection sensor according to claim 1, wherein, Photoelectric detection includes two filter plates, two detectors, and a circuit part. Each light source, filter plate, and photoelectric detector is on the same horizontal line, and the optical path from each light source to the detector is the same.

5. The adjustable range dual-light-source water quality COD detection sensor according to claim 4, characterized in that, The detector includes two photodiodes.

6. An adjustable-range dual-light-source water-quality COD detection sensor according to claim 4 or 5, characterized in that, The circuit part includes an analog amplification module, a CPU processing module, a GPRS communication module, and a laser driver chip for voltage-regulated current, which are welded on a circuit board. At the same time, the circuit board is externally connected with wires, connection data lines, and wires between various parts of the circuit.

7. The adjustable-range dual-light-source water-quality COD detection sensor according to claim 6, characterized in that, The laser driver chip for voltage-regulated current is pulse-modulated by a single-chip microcomputer to adjust the PWM duty cycle, and the output pulse signal is transmitted to the driver chip to change the circuit voltage, thereby changing the circuit current.

8. An adjustable range dual-light-source water quality COD detection sensor according to claim 1, characterized in that, The exterior of the housing is a cylindrical housing. There is a flat platform inside the housing. The transparent sliding partition and the transparent fixed partition are both arranged on the platform, and the space formed by the platform and the housing is divided into a light source part, an absorption chamber part, and a photoelectric detection part.

9. The adjustable-range dual-light-source water-quality COD detection sensor according to claim 1, characterized in that There is a wire groove on the housing that penetrates the power supply part, the absorption chamber part, and the photoelectric detection part for placing the circuit, and the wire groove is sealed with a transparent cover on the top.

10. The adjustable-range dual-light-source water-quality COD detection sensor according to claim 6, characterized in that, The analog amplification module is an amplification circuit composed of triodes.

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