Multi-parameter water quality sensor

Abstract

A multi-parameter water quality sensor comprises a shell, and a first water quality detection module, a second water quality detection module and a control and data processing cabin are installed on the shell. The first water quality detection module is used for measuring a first water quality parameter through an electrochemical or ion selection mode; the second water quality detection module is used for measuring a second water quality parameter in an optical mode, the first water quality parameter is a water quality parameter suitable for being measured in an electrochemical or ion selection mode, and the second water quality parameter is a water quality parameter suitable for being measured in an optical mode; the first water quality detection module is integrated with a probe used for measuring various water quality parameters suitable for being measured in a chemical or ion selection mode, the second water quality detection module comprises an optical channel, when the optical channel makes contact with air or water, air or water enters the optical channel, external light is prevented from entering the optical channel, and an optical water quality measuring instrument is arranged in the optical channel. The optical water quality measuring instrument is used for measuring water quality parameters suitable for being measured in an optical mode.

Description

Technical Field

[0001] The invention relates to the field of water quality detection, and in particular to a multi-parameter water quality sensor. Background Art

[0002] In the field of water quality testing, the parameters that need to be tested include: oil content in water, turbidity, COD (chemical oxygen demand), chlorophyll content, blue-green algae content, OD (dissolved oxygen), etc. Currently, water quality testing includes single-parameter measurement and multi-parameter measurement. The single-parameter measurement method can only measure one parameter. When it comes to measuring multiple parameters, multiple measuring instruments are required for multiple measurements, which is time-consuming and labor-intensive. The industry's implementation of multi-parameter measurement is based on the integration of various single-parameter sensors. The volume and weight will increase significantly. Summary of the invention

[0003] In view of the technical defects and technical drawbacks in the prior art, the embodiments of the present invention provide a multi-parameter water quality sensor that overcomes the above problems or at least partially solves the above problems. The specific solution is as follows:

[0004] A multi-parameter water quality sensor comprises a housing, on which a first water quality detection module, a second water quality detection module and a control and data processing cabin are mounted; the first water quality detection module is used to measure a first water quality parameter by electrochemical or ion selection; the second water quality detection module is used to measure a second water quality parameter by optical means, the first water quality parameter is a water quality parameter suitable for measurement by electrochemical or ion selection, and the second water quality parameter is a water quality parameter suitable for measurement by optical means;

[0005] Among them, the first water quality detection module is integrated with a probe for measuring various water quality parameters suitable for measurement by chemical or ion selection methods, and the second water quality detection module includes an optical channel, which allows air or water to enter when it contacts air or water, and blocks external light from entering. An optical water quality meter is arranged in the optical channel, and the optical water quality meter is used to measure water quality parameters suitable for optical measurement.

[0006] Further, the optical water quality measuring instrument comprises a light emitting unit, a light receiving unit, a grating and an imaging module;

[0007] The light emitting unit is used to emit a light signal, the light receiving unit is used to receive a light signal and measure the intensity of the received light signal, the light receiving unit has a through hole for allowing part of the light signal to pass through, the light signal passing through the through hole is incident on the grating and forms stripes on the grating, the imaging module is used to image a group of stripes on the grating and obtain a spectrum curve, the control and data processing cabin is used to compare the spectrum curve and the light signal intensity measured by the light receiving unit with the corresponding reference data, obtain the characteristic spectrum of the corresponding water quality, and obtain the corresponding water quality parameter through the characteristic spectrum of the corresponding water quality.

[0008] Furthermore, the optical water quality meter also includes a slit unit, which is located between the through hole and the grating. The light signal passing through the through hole is incident on the grating through the slit of the slit unit. The slit unit is used to control the intensity of the light signal incident on the grating by controlling the slit size, control the light direction and suppress stray light.

[0009] Furthermore, the first water quality detection module includes a water depth probe, a temperature probe, an ORP probe, an OD probe, a pH probe, a salinity and a conductivity probe; the water depth probe, the temperature probe, the ORP probe, the OD probe, the pH probe, the salinity and the conductivity probe are all electrically connected to the control and data processing cabin, and the first water quality parameters include water depth, temperature, ORP, OD, pH, salinity and conductivity parameters; the control and data processing cabin is used to measure the water depth, temperature, ORP, OD, pH, salinity and conductivity parameters of the water respectively through the water depth probe, the temperature probe, the ORP probe, the OD probe, the pH probe, the salinity and the conductivity probe.

[0010] Furthermore, the second water quality parameter includes oil content, turbidity, COD, chlorophyll content and blue-green algae content in water.

[0011] Furthermore, when the light emitting unit emits a light signal and there is no water in the light channel, the light signal detected by the light receiving unit and the spectral curve obtained by the imaging module are used as reference data; when the light emitting unit emits a light signal and the light channel is immersed in water, the light signal measured by the light receiving unit and the corresponding spectral curve obtained by the imaging module are compared with the corresponding reference data, and based on the difference between the light signal measured by the light receiving unit and the corresponding spectral curve obtained by the imaging module and the reference data, the characteristic spectrum of the corresponding water quality is obtained, and the corresponding water quality parameters are obtained by judging the characteristic spectrum.

[0012] Further, the light emitting unit includes one or more light emitting devices, and the light receiving unit includes one or more light receiving devices.

[0013] Furthermore, the light emitting device is a narrow spectrum or wide spectrum LED, and the light spectrum it emits includes ultraviolet light, visible light, infrared light, and excitation light spectra and characteristic absorption light spectra of various water parameters to be measured.

[0014] Furthermore, the light receiving device includes a narrow spectrum or a wide spectrum filter and a PD, and the light spectrum absorbed by it includes ultraviolet light, visible light, infrared light, and the fluorescence spectrum and characteristic absorption light spectrum of various water parameters to be measured.

[0015] Furthermore, the optical signal includes scattered, transmitted and reflected light.

[0016] The present invention has the following beneficial effects:

[0017] 1. A multi-parameter water quality sensor provided by the present invention is integrated with a first water quality detection module for measuring a first water quality parameter by electrochemical or ion selection, and a second water quality detection module and a control and data processing cabin for measuring a second water quality parameter by optical means. The first water quality parameter is a parameter that is better measured by electrochemical or ion selection than by optical means, and the second water quality parameter is a parameter that is better measured by optical means than by electrochemical or ion selection. The first water quality detection module is integrated with various probes suitable for measuring water quality by chemical or ion selection to achieve measurement of various corresponding water quality parameters in water. The second water quality detection module is a set of optical measuring instruments designed by the present invention, which complements the first water quality detection module to achieve measurement of various other water quality parameters in water.

[0018] 2. The present invention can realize the measurement types of existing multi-parameter sensors in the industry with a relatively light weight and has good scalability. For the parameters to be measured that can be covered by the optical measurement principle, the measurement types can be expanded through a simple program upgrade, and the development is fast and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A top view of a multi-parameter water quality sensor provided by an embodiment of the present invention;

[0020] Figure 2 A bottom view of a multi-parameter water quality sensor provided by an embodiment of the present invention;

[0021] Figure 3 A three-dimensional view of a multi-parameter water quality sensor provided by an embodiment of the present invention;

[0022] Figure 4 A three-dimensional cross-sectional view of a multi-parameter water quality sensor provided by an embodiment of the present invention;

[0023] Figure 5 Schematic diagram of a second water quality detection module provided by an embodiment of the present invention;

[0024] Figure 6 An imaging diagram of an imaging device provided by an embodiment of the present invention;

[0025] Figure 7 A spectrum curve diagram of an imaging device provided by an embodiment of the present invention;

[0026] Figure 8 A flow chart of water quality measurement using a multi-parameter water quality sensor provided in an embodiment of the present invention.

[0027] In the figure: 1. control and data processing cabin, 2. upper shell, 3. lower shell, 4. power supply and communication interface, 5. debugging port, 6. temperature probe, 7. salinity and conductivity probe, 8. OD probe, 9. water depth probe, 10. pH probe, 11. ORP probe, 13. optical channel, 14. imaging device, 15. grating, 16. slit, 17. light emitting and light receiving device, 18. supporting foot, 171. light emitting device, 172. light receiving device. DETAILED DESCRIPTION

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

[0029] like Figure 1-5 As shown, a multi-parameter water quality sensor provided as an embodiment of the present invention includes a housing, on which a first water quality detection module, a second water quality detection module and a control and data processing cabin 1 are installed; the first water quality detection module is used to measure a first water quality parameter by electrochemical or ion selection; the second water quality detection module is used to measure a second water quality parameter by optical means, the first water quality parameter is a water quality parameter suitable for measurement by electrochemical or ion selection, and the second water quality parameter is a water quality parameter suitable for measurement by optical means;

[0030] Among them, the first water quality detection module is integrated with a probe for measuring various water quality parameters suitable for measurement by chemical or ion selection methods, and the second water quality detection module includes an optical channel 13. When the optical channel 13 contacts air or water, air or water is allowed to enter it, and external light is blocked from entering it. An optical water quality meter is arranged in the optical channel 13, and the optical water quality meter is used to measure water quality parameters suitable for optical measurement.

[0031] In the above embodiments, water quality parameters suitable for measurement by electrochemical or ion selection methods are parameters that can only be measured by electrochemical or ion selection methods or that can be measured by electrochemical or ion selection methods with better accuracy or effect than those measured by optical methods; water quality parameters suitable for measurement by optical methods are parameters that can only be measured by optical methods or that can be measured by optical methods with better accuracy or effect than those measured by electrochemical or ion selection methods. Specifically, the present invention has concluded through testing that water depth, temperature, redox potential ORP, dissolved oxygen OD, pH, salinity and conductivity parameters are suitable for measurement by electrochemical or ion selection methods, while oil content, turbidity, chemical oxygen demand COD, chlorophyll content and blue-green algae content are measured by electro-optical methods.

[0032] As a preferred embodiment of the present invention, the first water quality detection module includes a water depth probe 9, a temperature probe 6, an ORP probe 11, an OD probe 8, a pH probe 10, and a salinity and conductivity probe 7; the water depth probe 9, the temperature probe 6, the ORP probe 11, the OD probe 8, the pH probe 10, the salinity and conductivity probe 7 are all electrically connected to the control and data processing cabin 1, and the control and data processing cabin is used to measure the water depth, temperature, ORP, OD, pH, salinity and conductivity parameters of the water through the water depth probe 9, the temperature probe 6, the ORP probe 11, the OD probe 8, the pH probe 10, the salinity and conductivity probe 7, respectively. Among them, by measuring the water depth, it is convenient to judge whether the entire sensor is immersed in water, and to measure the water quality parameters at different depths.

[0033] The present invention provides a multi-parameter water quality sensor, which is integrated with a first water quality detection module for measuring a first water quality parameter by electrochemical or ion selection and a second water quality detection module for measuring a second water quality parameter by optical means. The first water quality detection module is integrated with various probes suitable for measuring water quality by chemical or ion selection, so as to measure various corresponding water quality parameters in water. The second water quality detection module is a set of optical measuring instruments designed by the present invention, which complements the first water quality detection module and measures various other water quality parameters in water.

[0034] The present invention realizes the measurement types of existing multi-parameter sensors in the industry with a relatively light weight and has good scalability. For the parameters to be measured that can be covered by the optical measurement principle, the measurement types can be expanded through a simple program upgrade, and the development is fast and the cost is low.

[0035] As a preferred embodiment of the present invention, an optical water quality measuring instrument is also provided, the optical water quality measuring instrument comprises a light emitting unit, a light receiving unit, a slit unit 16, a grating 15 and an imaging module;

[0036] The light emitting unit is used to emit a light signal, the light receiving unit is used to receive a light signal and measure the intensity of the received light signal, the light receiving unit has a through hole for allowing part of the light signal to pass through, the slit unit 16 is located between the through hole and the grating 15, the light signal passing through the through hole is incident on the grating 15 through the slit 16 of the slit unit 16, and forms interference fringes on the grating 15 to decompose each spectral component, the slit unit 16 is used to control the intensity of the light signal incident on the grating 15 by controlling the size of the slit 16, control the light direction and suppress stray light, the imaging module is used to image a group of fringes on the grating 15 and obtain a spectral curve, the control and data processing cabin is used to compare the spectral curve and the light signal intensity measured by the light receiving unit with the corresponding benchmark data, and obtain the corresponding water quality parameter through the comparison result.

[0037] In the above embodiment: the optical channel 13 constitutes a relatively closed optical passage, air and water can enter freely, but external light is blocked and cannot enter; the optical emitting unit includes one or more optical emitting devices 171, and the optical receiving unit includes one or more optical receiving devices 172. The optical emitting device 171 and the optical receiving device 172 are respectively located at the two ends of the optical channel 13 and are arranged opposite to each other, so that the light emitted by the optical emitting device 171 is incident on the optical receiving device 172. The optical emitting device 171 includes but is not limited to narrow-spectrum or wide-spectrum LEDs, covering various ultraviolet light, visible light, infrared light, etc., as well as various excitation light spectra and characteristic absorption light spectra of water body parameters to be measured. The optical receiving device 172 includes but is not limited to narrow-spectrum or wide-spectrum filters and PDs, covering various ultraviolet light, visible light, infrared light, etc., as well as various fluorescence spectra and characteristic absorption light spectra of water body parameters to be measured. Each light emitting device 171 emits light in turn or in combination, and each light receiving device 172 detects in turn or in combination, and covers the characteristic spectrum of the measured water body; the imaging module: an imaging device 14 such as a CMOS camera, a CCD camera or a linear array CCD, images a group of stripes (such as the first main maximum stripe) on the grating 15, an imaging such as Figure 6 The color and intensity of each imaged part reflect the spectral characteristics of the light irradiated onto the grating 15 through the slit 16, and a spectral curve diagram is shown as Figure 7 shown.

[0038] When there is no water in the optical channel 13, it can be approximately considered that the optical channel 13 does not attenuate or scatter the light, and the optical signal detected by each optical receiving device 172 and the spectrum curve obtained by the imaging module can be used as the reference data. When the optical channel 13 is submerged in water, each optical receiving device 172 will also detect the corresponding optical signal, and the imaging module will also obtain the corresponding spectrum curve. By comparing with the reference data, the characteristic spectrum of the water quality in the optical channel 13 can be obtained, including absorption characteristics, scattering characteristics, fluorescence characteristics, etc.

[0039] like Figure 1-5 As shown, the shell includes an upper shell 2 and a lower shell 3, and the multi-parameter water quality sensor also includes a power supply and communication interface 4, a debugging port 5 and a support foot 18. The upper shell 2 and the lower shell 3 together form a closed, waterproof shell, providing a fixed basis for other components. The control and data processing cabin 1 is located between the upper and lower shells 3, providing sampling, communication, power supply, calculation and other related functions. The power supply and communication interface 4 provides an external cable interface for the entire sensor, including power supply and communication. The key debugging interfaces in the sensor are concentrated at the debugging port 5. The debugging port 5 is integrated on the upper shell 2 and can be opened or closed. By opening the debugging port 5, debugging can be conveniently performed without disassembling the entire shell. When the entire sensor is placed on a plane, the support foot 18 provides support to prevent other components from being damaged by friction and collision.

[0040] like Figure 8 As shown, it is a flow chart of using a multi-parameter water quality sensor to measure water quality according to an embodiment of the present invention, including:

[0041] Step 1: Start the multi-parameter water quality sensor and the machine will automatically complete the self-check.

[0042] Step 2, light up each light emitting device 171 in turn, and measure the intensity of the light signal through each light receiving device 172. The light signal passes through the slit 16 to reach the grating 15 and forms stripes on the grating 15. The imaging module is used to image a group of stripes on the grating 15 and obtain a spectrum curve. The data obtained in this step is used as the basic data;

[0043] Step 3, placing the multi-parameter water quality sensor into the water to be measured, and monitoring the water depth through the water depth probe 9;

[0044] Step 4, light up each light emitting device 171 in turn, and measure the light signal intensity through each light receiving device 172. The light signal passes through the slit 16 to reach the grating 15 and forms stripes on the grating 15. The imaging module is used to image a group of stripes on the grating 15 and obtain a spectral curve.

[0045] Step 5, comparing the data obtained in step 4 with the basic data obtained in step 2, obtaining characteristic spectra such as water absorption, scattering, and fluorescence, and obtaining corresponding water quality parameters through the characteristic spectra.

[0046] (1) Example of water quality parameter measurement based on absorption characteristic spectrum

[0047] The absorption characteristics of water samples to 254nm light source can reflect the COD parameters of water quality.

[0048] Generally speaking, COD has a linear relationship with its absorbance to a 254nm light source:

[0049] COD parameter to be measured

[0050] Absorbance of water sample to 254nm light source

[0051] Parameters and constants that need to be obtained during the calibration process.

[0052] Prepare multiple groups of water samples with different COD, use the water quality sensor to emit 254nm light source, measure the 254nm absorbance, use a standard COD meter to measure the real COD, establish a corresponding relationship table between 254nm absorbance and COD, and based on fitting methods such as the least squares method, you can obtain and complete the calibration.

[0053] (2) Example of water quality parameter measurement based on scattering characteristic spectrum

[0054] The absorption and scattering characteristics of water samples to 546nm light source can both reflect the turbidity parameters of water quality. Here we will use the scattering characteristics as an example to explain.

[0055] Prepare multiple groups of water samples with different turbidity, use the water quality sensor to emit a 546nm light source, measure the scattered light intensity at 546nm, use a standard turbidity meter to measure the actual turbidity, and establish a corresponding relationship table between the 546nm scattered light intensity and turbidity. In subsequent measurements, the turbidity can be measured by measuring the scattered light intensity.

[0056] (3) Examples of water quality parameter measurements based on fluorescence characteristic spectra

[0057] The fluorescence characteristics of water samples to 310nm light source can reflect the oil content in water quality. Oil content in water is generally used to reflect the pollution of water bodies by oil substances such as petroleum and gasoline.

[0058] Oil substances generally contain aromatic hydrocarbons. Aromatic hydrocarbons will be able to produce 360nm fluorescence under the excitation of a 310nm light source. When the intensity of the excitation light source is determined, the intensity of the fluorescence can reflect the concentration of aromatic hydrocarbons and thus reflect the oil parameters in the water.

[0059] Prepare multiple groups of water samples with different oil in water, use the water quality sensor to emit 310nm light source, measure the fluorescence intensity at 360nm, use a standard oil in water meter to measure the real turbidity, and establish a corresponding relationship table between 360nm fluorescence intensity and oil in water. In subsequent measurements, the measurement of oil in water can be achieved by measuring the 360nm fluorescence intensity.

[0060] Step 6, measuring the temperature, ORP, OD, pH, salinity and conductivity parameters of the water respectively through the temperature probe 6, ORP probe 11, OD probe 8, pH probe 10, salinity and conductivity probe 7.

[0061] Step 7, measurement completed.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-parameter water quality sensor, characterized in that: The invention comprises a shell, on which a first water quality detection module, a second water quality detection module and a control and data processing cabin are installed; the first water quality detection module is used to measure a first water quality parameter by electrochemical or ion selection; the second water quality detection module is used to measure a second water quality parameter by optical method, the first water quality parameter is a water quality parameter suitable for measurement by electrochemical or ion selection, and the second water quality parameter is a water quality parameter suitable for measurement by optical method; Among them, the first water quality detection module is integrated with a probe for measuring various water quality parameters suitable for measurement by chemical or ion selection methods, and the second water quality detection module includes an optical channel, which allows air or water to enter when it contacts air or water, and blocks external light from entering. An optical water quality meter is arranged in the optical channel, and the optical water quality meter is used to measure water quality parameters suitable for optical measurement.

2. The multi-parameter water quality sensor according to claim 1, characterized in that: The optical water quality measuring instrument comprises a light emitting unit, a light receiving unit, a grating and an imaging module; The light emitting unit is used to emit a light signal, the light receiving unit is used to receive a light signal and measure the intensity of the received light signal, the light receiving unit has a through hole for allowing part of the light signal to pass through, the light signal passing through the through hole is incident on the grating and forms stripes on the grating, the imaging module is used to image a group of stripes on the grating and obtain a spectral curve, and the control and data processing cabin is used to compare the spectral curve and the light signal intensity measured by the light receiving unit with the corresponding benchmark data, and obtain the corresponding water quality parameter through the comparison result.

3. The multi-parameter water quality sensor according to claim 2, characterized in that: The optical water quality measuring instrument also includes a slit unit, which is located between the through hole and the grating. The light signal passing through the through hole is incident on the grating through the slit of the slit unit. The slit unit is used to control the intensity of the light signal incident on the grating by controlling the size of the slit, control the light direction and suppress stray light.

4. The multi-parameter water quality sensor according to claim 1, characterized in that: The first water quality detection module includes a water depth probe, a temperature probe, an ORP probe, an OD probe, a pH probe, a salinity and a conductivity probe; the water depth probe, the temperature probe, the ORP probe, the OD probe, the pH probe, the salinity and the conductivity probe are all electrically connected to the control and data processing cabin, and the first water quality parameters include water depth, temperature, ORP, OD, pH, salinity and conductivity parameters; the control and data processing cabin is used to measure the water depth, temperature, ORP, OD, pH, salinity and conductivity parameters of the water respectively through the water depth probe, the temperature probe, the ORP probe, the OD probe, the pH probe, the salinity and the conductivity probe.

5. The multi-parameter water quality sensor according to claim 1, characterized in that: The second water quality parameters include oil content, turbidity, COD, chlorophyll content and blue-green algae content in water.

6. The multi-parameter water quality sensor according to claim 2, characterized in that: When the light emitting unit emits a light signal and there is no water in the light channel, the light signal detected by the light receiving unit and the spectral curve obtained by the imaging module are used as reference data; when the light emitting unit emits a light signal and the light channel is immersed in water, the light signal measured by the light receiving unit and the corresponding spectral curve obtained by the imaging module are compared with the corresponding reference data, and the corresponding water quality parameters are judged based on the difference between the light signal measured by the light receiving unit and the corresponding spectral curve obtained by the imaging module and the reference data.

7. The multi-parameter water quality sensor according to claim 1, characterized in that: The light emitting unit includes one or more light emitting devices, and the light receiving unit includes one or more light receiving devices.

8. The multi-parameter water quality sensor according to claim 7, characterized in that: The light emitting device is a narrow-spectrum or wide-spectrum LED, and the light spectrum it emits includes ultraviolet light, visible light, infrared light, and excitation light spectra and characteristic absorption light spectra of various water parameters to be measured.

9. The multi-parameter water quality sensor according to claim 7, characterized in that: The light receiving device includes a narrow-spectrum or wide-spectrum filter and a PD, and the light spectrum absorbed by it includes ultraviolet light, visible light, infrared light, and the fluorescence spectrum of various water parameters to be measured and the characteristic absorption light spectrum.

10. The multi-parameter water quality sensor according to claim 1, characterized in that: The optical signal includes scattered light, transmitted light and reflected light.

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