Method and device for online high-precision measurement of turbidity and total organic carbon

Abstract

The present invention provides a novel method and device for online high-precision measurement of turbidity and total organic carbon. The device includes a laser light source module, a water channel module, an optical path return module, a detector module and a data inversion module. Among them, the water channel module includes a cuvette; the optical path return module includes a first reflecting prism, a second reflecting prism, a reflector and a quartz lens; the detector module includes a first photodetector and a second photodetector. The present invention uses a laser light beam emitted by a laser light source module to detect sample water, so that the light intensity and spectral characteristics are stable and not affected by the test environment, which can effectively improve the sensitivity of water quality parameter measurement, and the laser light source module, the first reflecting prism, the cuvette, the reflector, the second reflecting prism and the quartz lens are arranged in sequence along the optical path, so that the laser light beam can be returned multiple times according to the preset optical path, thereby increasing the effective length of the action between the light beam and the sample water, reducing the lower limit of the measurement threshold, and improving the sensitivity of water quality parameter measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of water quality detection, and in particular to a novel method and device for online high-precision measurement of turbidity and total organic carbon. Background Art

[0002] Water plays a vital role in industry, agriculture, and even in people's daily lives. With the improvement of living standards, people have higher and higher requirements for water turbidity measurement. However, due to various man-made pollution and natural factors, water quality has changed. The quality of water determines whether the water source can be used. Turbidity is an important indicator for evaluating water quality. It is one of the simplest ways to determine whether a water source is polluted. Turbidity measurement is an important means of drinking water safety and water pollution monitoring. Therefore, the accurate determination of water turbidity is particularly important for the evaluation of water quality. Simple operation, high sensitivity, low threshold, and online monitoring are its development direction.

[0003] Currently, most turbidity measurement devices have low measurement accuracy, poor sensitivity, and are prone to secondary contamination. At the same time, a single sample cannot detect multiple parameters at the same time.

[0004] Total organic carbon is one of the important water quality indicators that reflects the pollution of water by organic matter. It refers to the total carbon content of dissolved and suspended organic matter in water. As a comprehensive indicator of organic matter, it can better represent the degree of organic pollution than BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand). It is a characteristic indicator of many pollution events, such as red tide, domestic polluted water and chemical wastewater. Total organic carbon is a newly developed indicator for evaluating organic pollution in water environment in recent years. It has been widely used in water quality monitoring of rivers, lakes, oceans and domestic water supply, as well as petrochemical, power generation and metallurgical industries.

[0005] At present, there are three methods for measuring total organic carbon: subtraction method, NPOC (non-purgeable organic carbon) method, spectroscopy method, and ultraviolet light intensity method. Among them, subtraction method and NPOC method are not real-time, and need to take samples to the laboratory or use large equipment to complete the test. Spectroscopy method is easily affected by other substances, thus affecting the analysis results. Summary of the invention

[0006] The purpose of the present invention is to provide a novel online high-precision method and device for measuring turbidity and total organic carbon, which can improve the measurement accuracy and sensitivity of water quality parameters, and realize real-time online detection of water quality parameters. It is not easily affected by other substances and has strong anti-interference ability. It can detect multiple water quality parameters such as water turbidity and total organic carbon at one time, thereby improving detection efficiency.

[0007] In order to solve the above technical problems, the first aspect of the present invention provides a novel online high-precision turbidity and total organic carbon measurement device, comprising: a laser light source module 10, a water channel module 20, an optical path return module 30, a detector module 40 and a data inversion module 50; the water channel module 20 comprises a cuvette 21; the optical path return module 30 comprises a first reflecting prism 31, a second reflecting prism 32, a reflector 33 and a quartz lens 34; the detector module 40 comprises a first photodetector 41 and a second photodetector 42; the data inversion module 50 is respectively connected to the first photodetector 41 and the second photodetector 42 for communication;

[0008] The cuvette 21 is filled with sample water; the laser light source module 10, the first reflecting prism 31, the cuvette 21, the reflector 33, the second reflecting prism 32 and the quartz lens 34 are arranged in sequence along the optical path, and the laser light beam emitted by the laser light source module 10 is reflected to the sample water by the first reflecting prism 31, the laser light beam transmitted by the sample water is sequentially reflected by the second reflecting prism 32, transmitted again by the sample water and reflected by the first reflecting prism 31 and transmitted to the second photodetector 42, and the laser light beam scattered by the sample water is sequentially reflected by the reflector 33 and converged by the quartz lens 34 and transmitted to the first photodetector 41.

[0009] Optionally, the laser light source module 10 includes a light source, a beam combiner 11 and a shaping lens group 12 arranged in sequence along the optical path, the light source outputs at least two laser light beams of different wavelengths, the beam combiner 11 combines the laser light beams of different wavelengths output by the light source and outputs them to the shaping lens group 12, and the shaping lens group 12 collimates the laser light beam output by the beam combiner 11.

[0010] Optionally, the first reflecting prism 31 is a right-angle prism, and both side surfaces of the first reflecting prism 31 forming a right angle are coated with a broadband reflecting film.

[0011] Optionally, the second reflecting prism 32 and the first reflecting prism 31 are of the same size, shape and material.

[0012] Optionally, the cuvette 21 is cylindrical in shape and is made of quartz material, and the ratio of the height of the cuvette 21 to its cross-sectional diameter is greater than 4.

[0013] Optionally, the height of the reflector 33 is equal to the height of the cuvette 21, and the reflector 33 is 360° arranged on the top surface of the cuvette 21 to surround the cuvette 21. The top of the reflector 33 is provided with an opening facing the cuvette 21, and the laser beam transmitted by the sample water is directly projected from the opening onto the second reflecting prism 32.

[0014] Optionally, the bottom end of the reflector 33 is fully open, and the opening diameter of the bottom end of the reflector 33 is at least equal to 4 times the height of the cuvette 21, the tangent direction of the position where the opening at the top end of the reflector 33 meets the side wall of the cuvette 21 has an angle range of 25 to 40° relative to the horizontal direction, and the tangent direction of the edge position of the bottom end of the reflector 33 has an angle range of 50 to 65° relative to the horizontal direction.

[0015] Optionally, the water channel module 20 further includes a water supply and drainage unit 22 , and a water inlet and a water overflow are respectively provided on the upper and lower ends of the side wall of the cuvette 21 , and the water supply and drainage unit 22 connects the water inlet and the water overflow to fill and discharge water from the cuvette 21 .

[0016] Optionally, the water supply and drainage unit 22 includes a micro-flow pump 221, a first baffle device 222, a drainage pump 223, a second baffle device 224 and a water level detection device 225; the first baffle device 222 is arranged between the cuvette 21 and the micro-flow pump 221, and the water inlet of the cuvette 21 is respectively connected to the first baffle device 222 and the drainage pump 223; the overflow port of the cuvette 21 is connected to the water level detection device 225 through the second baffle device 224.

[0017] Optionally, central axes of the cuvette 21 , the first reflecting prism 31 , the second reflecting prism 32 , the reflector 33 , and the quartz lens 34 coincide with each other.

[0018] Based on the novel online high-precision device for measuring turbidity and total organic carbon as described above, the second aspect of the present invention further provides a novel online high-precision method for measuring turbidity and total organic carbon, comprising:

[0019] S1, laser source module provides laser beam for high-precision turbidity and total organic carbon measurement;

[0020] S2, the water channel module provides sample water and performs sample processing on the sample water;

[0021] S3, the optical path reversing module performs reversing processing on the laser beam according to a preset optical path, so that the laser beam passes through the sample water, and obtains a scattered light signal and a transmitted light signal passing through the sample water;

[0022] S4, the detector module performs photoelectric conversion processing on the scattered light signal and the transmitted light signal to obtain electrical signals corresponding to the scattered light signal and the transmitted light signal respectively;

[0023] S5, a data inversion module obtains the turbidity value and the total organic carbon value of the sample water according to the inversion of the electrical signal.

[0024] Optionally, the laser beam in S1 includes one of a first wavelength beam, a second wavelength beam and a third wavelength beam, or a combined beam obtained by combining at least two of the first wavelength beam, the second wavelength beam and the third wavelength beam.

[0025] Optionally, before measuring the water turbidity and total organic carbon of the sample water, when the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, the method further includes:

[0026] S6, loading a plurality of first standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, obtaining a voltage value corresponding to each concentration of the first standard solution, and the data inversion module performing data fitting according to the concentration of each first standard solution and the voltage value corresponding to each concentration of the first standard solution to obtain a weighted value d1 of the first wavelength light beam in the scattered light signal and a weighted value d2 of the first wavelength light beam in the transmitted light signal, so as to obtain a first calibration relationship for measuring the turbidity of the sample water quality through the first wavelength light beam;

[0027] S7, when the cuvette is in a cavity state, the second photodetector performs photoelectric conversion on the second wavelength light beam in the transmitted light signal to obtain a first voltage value U1 corresponding to the second wavelength light beam;

[0028] S8, loading a plurality of second standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, and obtaining a voltage value corresponding to each concentration of the second standard solution. The data inversion module performs data fitting according to the concentration of each second standard solution, the voltage value corresponding to each concentration of the second standard solution, and the first voltage value U1, to obtain a second calibration relationship for measuring the total organic carbon value of the sample water quality through the second wavelength light beam.

[0029] Optionally, the first calibration relationship is as follows:

[0030] T=U2 / (d1*U2+d2*U3)

[0031] Among them, T is the turbidity value of the sample water, U2 is the second voltage value obtained by photoelectric conversion of the first wavelength light beam in the scattered light signal, U3 is the third voltage value obtained by photoelectric conversion of the first wavelength light beam in the transmitted light signal, d2 is the weighted value of the first wavelength light beam in the scattered light signal; d3 is the weighted value of the first wavelength light beam in the transmitted light signal.

[0032] Optionally, when the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, and the cuvette is loaded with the sample water, S4 includes:

[0033] S4.1, the first photodetector performs photoelectric conversion on the first wavelength light beam in the scattered light signal to obtain a second voltage value U2 corresponding to the first wavelength light beam;

[0034] S4.2, the second photodetector performs photoelectric conversion on the first wavelength light beam and the second wavelength light beam in the transmitted light signal to obtain a third voltage value U3 corresponding to the first wavelength light beam and a fourth voltage value U4 corresponding to the second wavelength light beam.

[0035] Optionally, the S5 includes:

[0036] S5.1, the data inversion module inverts and obtains the turbidity value of the sample water according to the second voltage value U2, the third voltage value U3 and the first calibration relationship;

[0037] S5.2, the data inversion module obtains the total organic carbon value of the sample water by inverting according to the fourth voltage value U4 and the second calibration relationship.

[0038] Compared with the prior art, the technical solution provided by the present invention has at least one of the following beneficial effects:

[0039] In a novel online high-precision turbidity and total organic carbon measurement method and device provided by the present invention, a laser light beam emitted by a laser light source module is used to detect sample water, so that the light intensity and spectral characteristics are stable and not affected by the test environment, which can effectively improve the sensitivity and anti-interference of water quality parameter measurement, and the laser light source module, the first reflecting prism, the cuvette, the reflector, the second reflecting prism and the quartz lens are arranged in sequence along the optical path, so that the laser light beam can be turned back multiple times according to the preset optical path, thereby increasing the effective length of the light beam and the water sample to be measured, thereby reducing the lower limit of the measurement threshold and improving the sensitivity of water quality parameter measurement.

[0040] Furthermore, in the novel online high-precision method and device for measuring turbidity and total organic carbon provided by the present invention, the scattered light signals collected at different angles can be automatically weighted by a reflector, thereby expanding the range of water turbidity measurement and improving the accuracy of water quality measurement. In addition, the influence of light intensity on the measurement results can be completely eliminated by setting up two photoelectric detectors and a data inversion module. The measuring device and method of the present invention can also detect multiple water quality parameters such as water turbidity and total organic carbon at one time, effectively improving the detection efficiency and saving time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A structural block diagram of a novel online high-precision device for measuring turbidity and total organic carbon provided in this embodiment;

[0042] Figure 2 A schematic diagram of the optical path system of a novel online high-precision turbidity and total organic carbon measurement device provided in this embodiment;

[0043] Figure 3 This is a flow chart of a novel online high-precision method for measuring turbidity and total organic carbon provided in this embodiment. DETAILED DESCRIPTION

[0044] As described in the background technology, water plays a vital role in industry, agriculture, and even in people's daily life. With the improvement of living standards, people have higher and higher requirements for water turbidity measurement. However, due to various man-made pollution and natural factors, water quality has changed. The quality of water quality determines whether the water source can be used. Turbidity is an important indicator for evaluating water quality. It is one of the simplest methods to judge whether a water source is polluted. Turbidity measurement is an important means for drinking water safety and water pollution monitoring. Therefore, the accurate determination of water turbidity is particularly important for the evaluation of water quality. Simple operation, high sensitivity, low threshold, and online monitoring are its development direction. Total organic carbon is one of the important water quality indicators that reflect that water quality is polluted by organic matter. It refers to the total amount of carbon in soluble and suspended organic matter in water. As a comprehensive indicator of organic matter, it can better represent the degree of organic pollution than BOD and COD. It is a characteristic indicator of various pollution events, such as red tide, domestic polluted water, and chemical wastewater. Total organic carbon is a newly developed indicator for evaluating organic pollution in water environment in recent years. It has been widely used in water quality monitoring of rivers, lakes, oceans and domestic water supply, as well as petrochemical, power generation and metallurgical industries.

[0045] At present, most turbidity measurement devices have low measurement accuracy, poor sensitivity, and are prone to secondary pollution. At the same time, a single sample cannot detect multiple parameters at the same time. In addition, the methods for measuring total organic carbon include subtraction, NPOC, spectroscopy, and ultraviolet light intensity. Among them, subtraction and NPOC methods are not real-time, and samples need to be taken to the laboratory or tested through large equipment. The spectroscopy method is easily affected by other substances, thus affecting the analysis results.

[0046] To this end, the present invention provides a novel online high-precision method and device for measuring turbidity and total organic carbon, which can improve the measurement accuracy and sensitivity of water quality parameters, and can realize real-time online detection of water quality parameters. It is not easily affected by other substances, has strong anti-interference ability, and can detect multiple water quality parameters such as water turbidity and total organic carbon at one time, thereby improving detection efficiency.

[0047] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0048] This embodiment provides a novel method and device for online high-precision measurement of turbidity and total organic carbon. Figure 1-3 The novel on-line high-precision method and device for measuring turbidity and total organic carbon of this embodiment are described.

[0049] refer to Figure 1 As shown, the embodiment provides a novel online high-precision turbidity and total organic carbon measurement device 1, comprising: a laser light source module 10, a water channel module 20, an optical path return module 30, a detector module 40 and a data inversion module 50. Figure 2 As shown, the water channel module 20 includes a cuvette 21; the optical path return module 30 includes a first reflecting prism 31, a second reflecting prism 32, a reflector 33 and a quartz lens 34; the detector module 40 includes a first photodetector 41 and a second photodetector 42; and the data inversion module 50 is respectively communicated with the first photodetector 41 and the second photodetector 42.

[0050] The cuvette 21 is filled with sample water; the laser light source module 10, the first reflecting prism 31, the cuvette 21, the reflector 33, the second reflecting prism 32 and the quartz lens 34 are arranged in sequence along the optical path, and the laser light beam emitted by the laser light source module 10 is reflected to the sample water by the first reflecting prism 31, the laser light beam transmitted by the sample water is sequentially reflected by the second reflecting prism 32, transmitted again by the sample water and reflected by the first reflecting prism 31 and transmitted to the second photodetector 42, and the laser light beam scattered by the sample water is sequentially reflected by the reflector 33 and converged by the quartz lens 34 and transmitted to the first photodetector 41.

[0051] In this embodiment, the central axes of the cuvette 21 , the first reflecting prism 31 , the second reflecting prism 32 , the reflector 33 and the quartz lens 34 coincide with each other.

[0052] It can be understood that, in this embodiment, the first photodetector 41 is arranged at the focal position of the quartz lens 34, and is used to receive the laser beam scattered by the sample water, and the second photodetector 42 is arranged on the reflection path of the laser beam transmitted by the sample water reflected by the first reflecting prism 31 for the second time, and is used to receive the laser beam transmitted by the sample water. The first photodetector 41 and the second photodetector 42 respectively perform photoelectric conversion on the scattered light signal and the transmitted light signal corresponding to the laser beam scattered by the sample water and the transmitted laser beam, respectively, to obtain electrical signals corresponding to the scattered light signal and the transmitted light signal, respectively, and then obtain the turbidity value and the total organic carbon value of the sample water by inverting the electrical signals through the data inversion module 50.

[0053] Please continue to refer to Figure 2 As shown, the laser light source module 10 includes a laser light source emission port, which is directly opposite to the outer wall of the right-angle side of the first reflecting prism 31; the laser light beam emitted by the laser light source emission port is returned multiple times by the optical path return module 30 to obtain a first reflection path a, a second reflection path b, a third reflection path c and a fourth reflection path d.

[0054] The first reflecting prism 31 is a right-angle prism, and both sides of the right-angled surfaces of the first reflecting prism 31 are coated with a broadband reflecting film. The first reflecting prism 31 reflects the laser beam emitted by the laser light source module 10 to obtain a first reflecting path a. The inner wall of a right-angled side surface of the second reflecting prism 32 reflects the laser beam on the first reflecting path a to obtain a second reflecting path b, the laser beam on the second reflecting path b is reflected by the inner wall of another right-angled side surface of the second reflecting prism 32 to obtain the third reflecting path c, and the laser beam on the third reflecting path c is reflected by the outer wall of another right-angled side surface of the first reflecting prism 31 to obtain the fourth reflecting path d.

[0055] In this embodiment, the second reflecting prism 32 and the first reflecting prism 31 have the same size, shape and material. In this embodiment, the first reflecting prism 31 and the second reflecting prism 32 are used to reflect the laser beam multiple times, so that the laser beam passes through the sample water multiple times and enhances the intensity of the scattered light obtained after the laser beam passes through the sample water.

[0056] It should be noted that the laser light source module 10 includes a light source, a beam combiner 11 and a shaping lens group 12 arranged in sequence along the optical path. The light source outputs at least two laser light beams of different wavelengths. The beam combiner 11 combines the laser light beams of different wavelengths output by the light source and outputs them to the shaping lens group 12. The shaping lens group 12 collimates the laser light beams output by the beam combiner 11.

[0057] The laser beam in this embodiment may include ultraviolet laser, near-infrared laser and blue laser, and the multiple lasers may be collimated and combined for output in the laser light source module 10, and the beam paths of the multiple lasers after combining are the same. In this embodiment, the wavelength of the laser beam output by the laser light source module 10 may be 850nm, 650nm and 275nm, and the light sources of the above three wavelength bands may be used alone or in combination. When used in combination, the above-mentioned beam combining mirror 11 may be used for beam combining and output.

[0058] In this embodiment, the cuvette 21 is cylindrical in shape and made of quartz material, and the ratio of the height of the cuvette 21 to its cross-sectional diameter is greater than 4. The cuvette 21 in this embodiment is a cylindrical hollow cuvette, which is used to load sample water or calibration solution. The cuvette 21 is made of quartz material and has good transmittance to the laser beam passing through the cuvette 21.

[0059] The height of the reflector 33 is equal to the height of the cuvette 21, and the reflector 33 is arranged on the top surface of the cuvette 21 at 360 degrees to surround the cuvette 21. The top of the reflector 33 is provided with an opening facing the cuvette 21, and the laser beam transmitted by the sample water is directly irradiated from the opening to the second reflecting prism 32. The bottom end of the reflector 33 is completely open, and the opening diameter of the bottom end of the reflector 33 is at least equal to 4 times the height of the cuvette 21. The angle range of the tangent direction of the position where the opening at the top end of the reflector 33 meets the side wall of the cuvette 21 relative to the horizontal direction is 25 to 40 degrees, and the angle range of the tangent direction of the edge position of the bottom end of the reflector 33 relative to the horizontal direction is 50 to 65 degrees.

[0060] Optionally, the top opening of the reflector 33 in this embodiment may be circular, and the size of the opening may be slightly larger than the cross-sectional diameter of the cuvette 21 so as to match the cross-sectional diameter of the cuvette 21 for installation. The absolute value of the curved surface slope of the reflector 33 at half the height is 1, and the angle of the tangent of the arc surface at the location is 45°. When the laser beam passes through the sample water, it can scatter light in different directions 360° around the central axis of the reflector 33 or the cuvette 21 on the path through the sample water, and is reflected and collected by the reflector 33 and incident on the quartz lens 34. Among them, the design of the reflector 33 will affect the collection of scattered light in different directions, that is, the scattered light in different directions is weighted under the action of the reflector 33, which can not only achieve the expansion of the parameter range of online measurement, but also calibrate the linearity of data fitting.

[0061] When the water quality is detected online in real time, the water channel module 20 also includes a water supply and drainage unit 22. A water inlet and an overflow port are respectively provided on the upper and lower ends of the side wall of the cuvette 21. The water supply and drainage unit 22 connects the water inlet and the overflow port to fill and discharge water from the cuvette 21.

[0062] The water supply and drainage unit 22 includes a micro-flow pump 221, a first baffle device 222, a drainage pump 223, a second baffle device 224 and a water level detection device 225; the first baffle device 222 is arranged between the cuvette 21 and the micro-flow pump 221, and the water inlet of the cuvette 21 is respectively connected to the first baffle device 222 and the drainage pump 223; the overflow port of the cuvette 21 is connected to the water level detection device 225 through the second baffle device 224.

[0063] Specifically, the micro-flow pump 221 is used to extract sample water from the water source to be tested in real time, and the first baffle device 222 performs de-bubbling treatment on the extracted sample water, and then transports the de-bubbled sample water to the cuvette 21. When the sample water overflows from the upper part of the cuvette 21, the overflowed sample water is de-bubbled by the second baffle device 224 and then transported to the water level detection device 225. If the water level detection device 225 detects that the level of the overflowed sample water reaches a preset threshold, the micro-flow pump 221 is triggered to stop working. Optionally, after the detection work is completed, the sample water or the solution used for test calibration loaded in the cuvette 21 can also be discharged by the drain pump 223 connected to the water inlet.

[0064] Further, based on the above-mentioned novel online high-precision turbidity and total organic carbon measurement device, the present invention also provides a novel online high-precision turbidity and total organic carbon measurement method, referring to Figure 3 As shown, the novel online high-precision method for measuring turbidity and total organic carbon includes the following steps:

[0065] S1, laser source module provides laser beam for high-precision turbidity and total organic carbon measurement;

[0066] S2, the water channel module provides sample water and performs sample processing on the sample water;

[0067] S3, the optical path reversing module performs reversing processing on the laser beam according to a preset optical path, so that the laser beam passes through the sample water, and obtains a scattered light signal and a transmitted light signal passing through the sample water;

[0068] S4, the detector module performs photoelectric conversion processing on the scattered light signal and the transmitted light signal to obtain electrical signals corresponding to the scattered light signal and the transmitted light signal respectively;

[0069] S5, a data inversion module obtains the turbidity value and the total organic carbon value of the sample water according to the inversion of the electrical signal.

[0070] In a novel online high-precision method for measuring turbidity and total organic carbon provided by the present invention, a laser light beam emitted by a laser light source module is used to detect sample water, so that the light intensity and spectral characteristics are stable and not affected by the test environment, which can effectively improve the sensitivity and anti-interference of water quality parameter measurement, and the laser light source module, the first reflecting prism, the cuvette, the reflector, the second reflecting prism and the quartz lens are arranged in sequence along the optical path, so that the laser light beam can be turned back multiple times according to the preset optical path, thereby increasing the effective length of the light beam and the water sample to be measured, thereby reducing the lower limit of the measurement threshold and improving the sensitivity of water quality parameter measurement.

[0071] In step S1, the laser light source module can provide a laser beam for high-precision turbidity and total organic carbon measurement. The laser beam in S1 may include one of a first wavelength beam, a second wavelength beam, and a third wavelength beam, or a combined beam obtained by combining at least two of the first wavelength beam, the second wavelength beam, and the third wavelength beam. That is, the laser beam may be a single laser beam, or a combined beam obtained by combining at least two laser beams.

[0072] Optionally, before measuring the water turbidity and total organic carbon of the sample water, when the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, the method further includes:

[0073] S6, loading a plurality of first standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, and obtaining a voltage value corresponding to each concentration of the first standard solution; the data inversion module performs data fitting according to the concentration of each first standard solution and the voltage value corresponding to each concentration of the first standard solution to obtain a weighted value d1 of the first wavelength light beam in the scattered light signal and a weighted value d2 of the first wavelength light beam in the transmitted light signal, so as to obtain a first calibration relationship for measuring the turbidity of the sample water quality through the first wavelength light beam.

[0074] Of course, before the cuvette 21 is loaded with the calibration solution, the method further includes:

[0075] S7, when the cuvette is in a cavity state, the second photodetector performs photoelectric conversion on the second wavelength light beam in the transmitted light signal to obtain a first voltage value U1 corresponding to the second wavelength light beam.

[0076] Specifically, the first wavelength light beam may be a 650nm laser beam, and the second wavelength light beam may be a 275nm laser beam. In this embodiment, the 650nm laser beam is used to measure water turbidity, and the 275nm laser beam is used to measure the total organic carbon value of water quality.

[0077] It should be noted that before measuring the water turbidity, the first calibration relationship mentioned above needs to be calibrated. The first calibration relationship is as follows:

[0078] T=U2 / (d1*U2+d2*U3)

[0079] Among them, T is the turbidity value of the sample water, U2 is the second voltage value obtained by photoelectric conversion of the first wavelength light beam in the scattered light signal, i.e., the 650nm laser light beam, U3 is the third voltage value obtained by photoelectric conversion of the first wavelength light beam in the transmitted light signal, i.e., the 650nm laser light beam, d2 is the weighted value of the first wavelength light beam in the scattered light signal; d3 is the weighted value of the first wavelength light beam in the transmitted light signal.

[0080] In this embodiment, in order to obtain the above-mentioned first calibration relationship, it is necessary to obtain the d1 value and the d2 value in the above-mentioned first calibration relationship. To this end, a formazin solution can be loaded in the cuvette 21 to calibrate the first calibration relationship for measuring water turbidity. When the cuvette 21 is filled with a formazin solution of concentration T1, the laser light source module emits a combined light beam obtained by combining a 650nm laser beam and a 275nm laser beam. The first photodetector receives the scattered laser beam and converts the laser signal of the 650nm wavelength in the scattered laser beam into a voltage signal U21, and then the second photodetector receives the transmitted laser beam and converts the laser signal of the 650nm wavelength in the transmitted laser beam into a voltage signal U31.

[0081] Among them, U21 = K21*I21, U31 = K31*I31. K21 and K31 are the circuit amplification coefficients of the amplifier circuits inside the first photodetector and the second photodetector. I21 and I31 are the photocurrent of scattered light and the photocurrent of transmitted light, respectively. Among them, I21 is the photocurrent generated by the weighted superposition of lasers with different scattering directions and 360° around the axis through the reflector, and its formula is as follows: Where η is the loudness of the first photodetector; R θ Determined by the design characteristics of the reflector, parameter R θ Determines the weighting of light in different scattering directions.

[0082] Further, the formazine solution of different concentrations (such as the standard solution concentration is above 20NTU) is repeatedly loaded in the cuvette to obtain the voltage value corresponding to each standard solution concentration. For example, for the formazine solution with a concentration of T2, the voltage signals U22 and U32 are obtained correspondingly, and the operation is repeated until n groups of mapping data for calibration are obtained, and the weighted value d1 of the 650nm wavelength light signal in the scattered light signal and the weighted value d2 of the 650nm wavelength light signal in the transmitted light signal are fitted through the n groups of mapping data to obtain the first calibration relationship, thereby constructing the relationship between the first standard solution concentration and the photovoltage: T=U2 / (d1*U2+d2*U3). In this embodiment, the first calibration relationship obtained by multiple calibrations can eliminate the influence of light source fluctuations on the measurement results.

[0083] When measuring the total organic carbon value of water quality, the numerical relationship between light intensity and total organic carbon, i.e., the second calibration relationship, can also be established in advance by calibration with standard solution. However, before obtaining the second calibration relationship, the first voltage value U1 corresponding to the reference value of the light intensity of the cuvette cavity needs to be obtained.

[0084] Specifically, the light source can be turned on first, and the second photodetector continuously collects the light intensity value corresponding to the laser light beam of the second wavelength, i.e., 275nm wavelength, and selects the calculation window. When the standard deviation σ of the light intensity value and the RMS percentage are less than 3%, the work can be started, and then the light intensity value of the cavity at this time is saved, and the first voltage value U1 corresponding to the cavity light intensity reference value is updated, and the total organic carbon value is inverted according to the light intensity value during the current test based on this first voltage value U1 reference value, and the temperature compensation algorithm is used in the actual process to improve the accuracy of the total organic carbon measurement.

[0085] After obtaining the first voltage value U1 corresponding to the reference value of the light intensity of the cuvette cavity, the method further includes:

[0086] S8, loading a plurality of second standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, and obtaining a voltage value corresponding to each concentration of the second standard solution. The data inversion module performs data fitting according to the concentration of each second standard solution, the voltage value corresponding to each concentration of the second standard solution, and the first voltage value U1, to obtain a second calibration relationship for measuring the total organic carbon value of the sample water quality through the second wavelength light beam.

[0087] Similarly, potassium diphosphate solutions of various concentrations are loaded in a cuvette, the laser light source module outputs a combined light beam, the second photodetector receives the transmitted light signal, and performs photoelectric conversion on the light signal of the second wavelength, i.e., 275 nm, in the transmitted light signal, so as to obtain voltage values ​​corresponding to potassium diphosphate solutions of various concentrations, and then obtain multiple sets of calibration data in a mapping relationship, and obtain a second calibration relationship for measuring the total organic carbon value of the sample water quality based on the multiple sets of calibration data.

[0088] Optionally, when the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, and the cuvette is loaded with the sample water, S4 includes:

[0089] S4.1, the first photodetector performs photoelectric conversion on the first wavelength light beam in the scattered light signal to obtain a second voltage value U2 corresponding to the first wavelength light beam.

[0090] S4.2, the second photodetector performs photoelectric conversion on the first wavelength light beam and the second wavelength light beam in the transmitted light signal to obtain a third voltage value U3 corresponding to the first wavelength light beam and a fourth voltage value U4 corresponding to the second wavelength light beam.

[0091] Optionally, the S5 includes:

[0092] S5.1, the data inversion module inverts and obtains the turbidity value of the sample water according to the second voltage value U2, the third voltage value U3 and the first calibration relationship;

[0093] S5.2, the data inversion module obtains the total organic carbon value of the sample water by inverting according to the fourth voltage value U4 and the second calibration relationship.

[0094] Specifically, when the cuvette is loaded with sample water, the laser light source module emits a combined light beam obtained by combining a 650nm wavelength laser beam and a 275nm laser beam, the first photodetector performs photoelectric conversion on the 650nm wavelength light signal in the scattered light signal to obtain a second voltage value U2 corresponding to the 650nm wavelength light signal, and the second photodetector performs photoelectric conversion on the 650nm wavelength light signal in the transmitted light signal to obtain a third voltage value U3 corresponding to the 650nm wavelength light signal. The data inversion module substitutes the second voltage value U2 and the third voltage value U3 into the first calibration relationship to invert and obtain the turbidity value of the sample water.

[0095] Optionally, the second photodetector further performs photoelectric conversion on the 275nm wavelength light signal in the transmitted light signal to obtain a fourth voltage value U4 corresponding to the 275nm wavelength light signal. The data inversion module substitutes the fourth voltage value U4 into the second calibration relationship to invert and obtain the total organic carbon value of the sample water.

[0096] In summary, in a novel online high-precision method and device for measuring turbidity and total organic carbon provided by the present invention, a laser light beam emitted by a laser light source module is used to detect sample water, so that the light intensity and spectral characteristics are stable and not affected by the test environment, which can effectively improve the sensitivity and anti-interference of water quality parameter measurement, and the laser light source module, the first reflecting prism, the cuvette, the reflector, the second reflecting prism and the quartz lens are arranged in sequence along the optical path, so that the laser light beam can be turned back multiple times according to the preset optical path, thereby increasing the effective length of the light beam and the water sample to be measured, thereby reducing the lower limit of the measurement threshold and improving the sensitivity of water quality parameter measurement.

[0097] Furthermore, in the novel online high-precision method and device for measuring turbidity and total organic carbon provided by the present invention, the scattered light signals collected at different angles can be automatically weighted by a reflector, thereby expanding the range of water turbidity measurement and improving the accuracy of water quality measurement. In addition, the influence of light intensity on the measurement results can be completely eliminated by setting up two photoelectric detectors and a data inversion module. The measuring device and method of the present invention can also detect multiple water quality parameters such as water turbidity and total organic carbon at one time, effectively improving the detection efficiency and saving time costs.

[0098] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of protection of the present invention. Any changes or modifications made by a person of ordinary skill in the art based on the above disclosure shall fall within the scope of protection of the present invention.

[0099] It should be noted that, although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

[0100] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An online high-precision device for measuring turbidity and total organic carbon, characterized in that: include: A laser light source module (10), a water channel module (20), an optical path return module (30), a detector module (40) and a data inversion module (50); the water channel module (20) comprises a cuvette (21); the optical path return module (30) comprises a first reflecting prism (31), a second reflecting prism (32), a reflector (33) and a quartz lens (34); the detector module (40) comprises a first photodetector (41) and a second photodetector (42); the data inversion module (50) is respectively connected to the first photodetector (41) and the second photodetector (42); The cuvette (21) contains sample water; the laser light source module (10), the first reflection prism (31), the cuvette (21), the reflector (33), the second reflection prism (32) and the quartz lens (34) are arranged in sequence along the optical path; the laser light beam emitted by the laser light source module (10) is reflected to the sample water via the first reflection prism (31); the laser light beam transmitted by the sample water is sequentially reflected by the second reflection prism (32), re-transmitted by the sample water and reflected by the first reflection prism (31) and transmitted to the second photoelectric detector (42); the laser light beam scattered by the sample water is sequentially reflected by the reflector (33) and converged by the quartz lens (34) and transmitted to the first photoelectric detector (41).

2. The online high-precision turbidity and total organic carbon measurement device according to claim 1, characterized in that: The laser light source module (10) comprises a light source, a beam combiner (11) and a shaping lens group (12) arranged in sequence along an optical path; the light source outputs at least two laser light beams of different wavelengths; the beam combiner (11) combines the laser light beams of different wavelengths output by the light source and outputs them to the shaping lens group (12); and the shaping lens group (12) performs collimation processing on the laser light beams output by the beam combiner (11).

3. The online high-precision turbidity and total organic carbon measurement device according to claim 1, characterized in that: The first reflecting prism (31) is a right-angle prism, and both sides of the first reflecting prism (31) forming a right angle are coated with a broadband reflecting film.

4. The device for online high-precision measurement of turbidity and total organic carbon as claimed in claim 3, characterized in that: The second reflecting prism (32) and the first reflecting prism (31) are of the same size, shape and material.

5. The online high-precision turbidity and total organic carbon measurement device according to claim 1, characterized in that: The cuvette (21) is cylindrical in shape and is made of quartz material. The ratio of the height of the cuvette (21) to its cross-sectional diameter is greater than 4.

6. The device for online high-precision measurement of turbidity and total organic carbon according to claim 5, characterized in that: The height of the reflector (33) is equal to that of the cuvette (21), and the reflector is arranged 360° on the top surface of the cuvette (21) to surround the cuvette (21). The top of the reflector (33) is provided with an opening facing the cuvette (21), and the laser beam transmitted by the sample water is directly projected from the opening onto the second reflecting prism (32).

7. The device for online high-precision measurement of turbidity and total organic carbon according to claim 6, characterized in that: The bottom end of the reflector (33) is completely open, and the opening diameter of the bottom end of the reflector (33) is at least equal to 4 times the height of the cuvette (21), the tangent direction of the position where the opening at the top end of the reflector (33) meets the side wall of the cuvette (21) has an angle range of 25 to 40° relative to the horizontal direction, and the tangent direction of the edge position of the bottom end of the reflector (33) has an angle range of 50 to 65° relative to the horizontal direction.

8. The on-line high-precision turbidity and total organic carbon measurement device according to claim 1, characterized in that: The water channel module (20) further comprises a water supply and drainage unit (22), and a water inlet and a water overflow are respectively provided on the upper and lower ends of the side wall of the cuvette (21), and the water supply and drainage unit (22) is connected to the water inlet and the water overflow to fill and discharge water from the cuvette (21).

9. The device for online high-precision measurement of turbidity and total organic carbon according to claim 8, characterized in that: The water supply and drainage unit (22) comprises a micro-flow pump (221), a first baffle device (222), a drainage pump (223), a second baffle device (224) and a water level detection device (225); the first baffle device (222) is arranged between the cuvette (21) and the micro-flow pump (221), and the water inlet of the cuvette (21) is respectively connected to the first baffle device (222) and the drainage pump (223); the overflow port of the cuvette (21) is connected to the water level detection device (225) via the second baffle device (224).

10. The device for online high-precision measurement of turbidity and total organic carbon according to any one of claims 1 to 9, characterized in that: The central axes of the cuvette (21), the first reflecting prism (31), the second reflecting prism (32), the reflector (33) and the quartz lens (34) coincide with each other.

11. An online high-precision method for measuring turbidity and total organic carbon based on the online high-precision device for measuring turbidity and total organic carbon according to any one of claims 1 to 10, characterized in that: include: S1, laser source module provides laser beam for high-precision turbidity and total organic carbon measurement; S2, the water channel module provides sample water and performs sample processing on the sample water; S3, the optical path reversing module performs reversing processing on the laser beam according to a preset optical path, so that the laser beam passes through the sample water, and obtains a scattered light signal and a transmitted light signal passing through the sample water; S4, the detector module performs photoelectric conversion processing on the scattered light signal and the transmitted light signal to obtain electrical signals corresponding to the scattered light signal and the transmitted light signal respectively; S5, a data inversion module obtains the turbidity value and the total organic carbon value of the sample water according to the inversion of the electrical signal.

12. The method for online high-precision measurement of turbidity and total organic carbon according to claim 11, characterized in that: The laser beam in S1 includes one of a first wavelength beam, a second wavelength beam and a third wavelength beam, or a combined beam obtained by combining at least two of the first wavelength beam, the second wavelength beam and the third wavelength beam.

13. The method for online high-precision measurement of turbidity and total organic carbon according to claim 12, characterized in that: Before measuring the water turbidity and total organic carbon of the sample water, when the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, the method further includes: S6, loading a plurality of first standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, obtaining a voltage value corresponding to each concentration of the first standard solution, and the data inversion module performing data fitting according to the concentration of each first standard solution and the voltage value corresponding to each concentration of the first standard solution to obtain a weighted value d1 of the first wavelength light beam in the scattered light signal and a weighted value d2 of the first wavelength light beam in the transmitted light signal, so as to obtain a first calibration relationship for measuring the turbidity of the sample water quality through the first wavelength light beam; S7, when the cuvette is in a cavity state, the second photodetector performs photoelectric conversion on the second wavelength light beam in the transmitted light signal to obtain a first voltage value U1 corresponding to the second wavelength light beam; S8, loading a plurality of second standard solutions of different concentrations in the cuvette, performing a plurality of experimental calibrations respectively, and obtaining a voltage value corresponding to each concentration of the second standard solution. The data inversion module performs data fitting according to the concentration of each second standard solution, the voltage value corresponding to each concentration of the second standard solution, and the first voltage value U1, to obtain a second calibration relationship for measuring the total organic carbon value of the sample water quality through the second wavelength light beam.

14. The method for online high-precision measurement of turbidity and total organic carbon according to claim 13, characterized in that: The first calibration relationship is as follows: T=U2 / (d1*U2+d2*U3) Among them, T is the turbidity value of the sample water, U2 is the second voltage value obtained by photoelectric conversion of the first wavelength light beam in the scattered light signal, U3 is the third voltage value obtained by photoelectric conversion of the first wavelength light beam in the transmitted light signal, d2 is the weighted value of the first wavelength light beam in the scattered light signal; d3 is the weighted value of the first wavelength light beam in the transmitted light signal.

15. The method for online high-precision measurement of turbidity and total organic carbon according to claim 14, characterized in that: When the laser beam is a combined beam obtained by combining the first wavelength beam and the second wavelength beam, and the cuvette is loaded with the sample water, S4 includes: S4.1, the first photodetector performs photoelectric conversion on the first wavelength light beam in the scattered light signal to obtain a second voltage value U2 corresponding to the first wavelength light beam; S4.2, the second photodetector performs photoelectric conversion on the first wavelength light beam and the second wavelength light beam in the transmitted light signal to obtain a third voltage value U3 corresponding to the first wavelength light beam and a fourth voltage value U4 corresponding to the second wavelength light beam.

16. The method for online high-precision measurement of turbidity and total organic carbon according to claim 15, characterized in that: The S5 includes: S5.1, the data inversion module inverts and obtains the turbidity value of the sample water according to the second voltage value U2, the third voltage value U3 and the first calibration relationship; S5.2, the data inversion module obtains the total organic carbon value of the sample water by inverting according to the fourth voltage value U4 and the second calibration relationship.

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