CN107561157B - Water quality detector and method thereof - Google Patents
Water quality detector and method thereof Download PDFInfo
- Publication number
- CN107561157B CN107561157B CN201610507308.4A CN201610507308A CN107561157B CN 107561157 B CN107561157 B CN 107561157B CN 201610507308 A CN201610507308 A CN 201610507308A CN 107561157 B CN107561157 B CN 107561157B
- Authority
- CN
- China
- Prior art keywords
- harmonic
- signal
- water quality
- voltage amplitude
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/20—Controlling water pollution; Waste water treatment
Abstract
The invention provides a water quality detector and a method thereof, wherein the water quality detector comprises a transmitting transducer, a detecting tank and a water quality detector, wherein the transmitting transducer is used for inputting ultrasonic signals generated according to excitation voltage into the detecting tank; the receiving transducer is used for collecting ultrasonic signals with waveform distortion generated by the non-uniform aqueous medium in the detection pool, and the ultrasonic signals comprise subharmonic signals; the filtering module is used for filtering baseband noise and higher harmonics in the harmonic signals to obtain second and third harmonic signals; the controller is used for carrying out analog-digital conversion on the second harmonic signal and the third harmonic signal, respectively calculating voltage amplitude values corresponding to the second harmonic signal and the third harmonic signal in preset time, and detecting the water quality condition according to the ratio of the voltage amplitude values to the square of the excitation voltage amplitude value of the corresponding transmitting transducer and the square of the third power; and the display is used for displaying the water quality condition of the detection pool. Compared with other ultrasonic water quality detection modes, the method reduces the problems of water quality detection precision and efficiency reduction caused by cavitation phenomenon, and is suitable for wide families.
Description
Technical Field
The invention relates to the technical field of ultrasonic measurement, in particular to a water quality detector and a method thereof.
Background
The quality of drinking water greatly influences the daily life and health of people, and governments and scientists around the world pay great attention to drinking water safety. However, with the development of economy and the increase of population, water resources in a plurality of areas are in shortage, and the pollution of drinking water sources is serious, so that the safety of resident life drinking water is threatened. In order to ensure the safety of drinking water, the ministry of health and the national standards administration (national institutes of standardization) revised the "sanitary Standard for Drinking Water" issued in 1985 (GB 5749-85), and issued a new mandatory national "sanitary Standard for Drinking Water" (GB 5749-2006) in combination. Thus, although the safety of the produced drinking water is ensured, the pollution of the drinking water can be generated in the process of water transmission, storage and use, and the pollution of the water quality can be generated, especially, secondary water supply is adopted in many cities, so that the water pollution opportunity is greatly increased. In order to ensure the safety of water, it is necessary to conveniently detect the water quality at the use terminal.
The pollution substances of the drinking water are numerous and are classified into: there are inorganic contamination, organic contamination, bacterial contamination and radioactive contamination. In order to ensure drinking water safety, the content of all substances needs to be detected, the content is mainly determined by chemical reaction of the substances, and different chemical analysis methods need to be adopted for identifying different chemical substances. In order to rapidly and simply analyze the water quality, people rapidly detect the pollution condition of the drinking water according to the change of physical properties of the drinking water after the drinking water is dissolved into pollutants. The simplest and effective method is to scatter the light incident into the water after the pollutant is insufficiently dissolved and suspended in the water, so that the water is easy to generate turbidity, and the pollution condition of the water is detected according to the turbidity of the water, but when the pollutant has good solubility or small substance particles, the light is scattered very little, the change of the turbidity is very small, and the pollution condition of the water is difficult to be determined by the turbidity, in addition, the turbidity is very large along with the background illumination condition, so that the method can only make preliminary judgment.
The other method is a conductivity detection method, because a plurality of pollutants are dissolved in water, the quantity of conductive ions in the water is changed, so that the change of the conductivity of the water is easy to cause, therefore, the pollution condition of the water can be determined by measuring the conductivity of the water, the conductivity of the solution is related to factors such as the temperature, polarization phenomenon on an electrode, the distribution capacitance of the electrode and the like, so that the conductivity is very sensitive to the operation process and the environment, and the method is difficult to be widely used in families.
There is also a method for detecting water pollution using a change in physical properties, for example, an oxygen dissolution amount detection method, which inevitably increases the gas content in water when the pollutant is dissolved in water, and determines the water pollution by detecting the oxygen dissolution amount in water. At present, although a plurality of oxygen dissolution water quality detectors exist, a common chemical measurement method is not suitable for simple measurement due to difficult operation. The existing simple measurement method is dissolved oxygen electrode, the current measurement method is used for measuring the content of dissolved oxygen in water according to the diffusion rate of molecular oxygen through a film, the current measurement method is high in measurement speed, simple and convenient to operate, less in interference and capable of automatically and continuously detecting on site, but because the oxygen permeable film and the electrode are easier to age, when algae, sulfides, carbonates, oils and other substances are contained in a water sample, the oxygen permeable film can be blocked or damaged, protection and timely replacement are needed, and because the oxygen concentration is measured by means of oxidation-reduction reaction of the electrode under the action of oxygen, oxygen is consumed in the measurement process, the sample is continuously stirred in the measurement process, the general speed is at least required to be 0.3m/s, and electrolyte is required to be replaced regularly, so that the measurement accuracy and response time of the water sample are limited by diffusion factors. The above problems make the method difficult to popularize in the home. In order to simply and quickly detect the pollution of drinking water, a new method is needed to be adopted for the pollution of the drinking water.
Since the dissolution of substances into water changes the acoustic properties of the water, such as sound velocity, absorption coefficient, scattering coefficient, etc., it has long been known to determine the content of substances in water by detecting these parameters. However, as long as the amount of material dissolved is not large, these acoustic properties of the water change very little, so that these methods can only be used in very polluted cases, which are easily replaced by other simple detection methods.
However, the characteristics of more pollutants and larger gas content in water can be utilized, and cavitation effect can be used for detection. When the ultrasonic wave with larger intensity is in the water, the oscillation of the ultrasonic wave in the water gradually enlarges the small bubbles in the water, finally the bubbles are broken, and the broken bubbles emit ultrasonic waves, which is called cavitation phenomenon. By detecting the threshold value of ultrasonic sound pressure output by the ultrasonic transducer generated by cavitation effect, the gas content in water can be evaluated in principle, so that the pollution condition of the water can be judged. However, since the cavitation threshold is not only related to many factors such as the ambient temperature, the material type, the distance from the transducer, etc., but also related to the initial size of cavitation bubbles, the size of cavitation bubbles in water is not constant but is distributed in probability according to a certain distribution function, so the cavitation threshold is not actually a certain amount, and thus the cavitation threshold measured by cavitation phenomenon is actually the receiving sensitivity of cavitation signals, and it is difficult to determine the pollution condition of water by this method.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a water quality detector and a method thereof, which are used for solving the problems of inconvenient operation and low detection precision of the water quality detector in the prior art, and cannot be popularized to home use.
To achieve the above and other related objects, the present invention provides a water quality detector, including a detection cell, a transmitting transducer, a receiving transducer, a controller, a filter circuit and a display;
the transmitting transducer is used for inputting ultrasonic signals generated according to the excitation voltage into the detection pool;
the receiving transducer is used for collecting ultrasonic signals with waveform distortion generated by the non-uniform water medium in the detection pool, wherein the ultrasonic signals comprise harmonic signals;
the filtering module is arranged between the receiving transducer and the controller and is used for filtering baseband noise and higher harmonics in each subharmonic signal to obtain second and third harmonic voltage signals;
the controller is used for carrying out analog-to-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal, respectively calculating voltage amplitude values corresponding to the second harmonic voltage signal and the third harmonic voltage signal in preset time, and detecting water quality according to square and third-order ratio values of the voltage amplitude values of the second harmonic and the third harmonic and the excitation voltage amplitude values of the corresponding transmitting transducers;
the display is connected to the output end of the controller and used for displaying the water quality condition of the detection pool.
Another object of the present invention is to provide a water quality testing method, comprising:
introducing water to be detected into a detection pool;
transmitting ultrasonic signals into the detection cell under the excitation voltage;
the method comprises the steps that a receiving transducer collects ultrasonic signals with waveform distortion generated by a non-uniform water medium in a detection pool, wherein the ultrasonic signals comprise subharmonic signals;
filtering baseband noise and higher harmonics in each harmonic signal to obtain second and third harmonic voltage signals;
analog-digital conversion is carried out on the second harmonic voltage signal and the third harmonic voltage signal, voltage amplitude values corresponding to the analog-digital converted second harmonic signal and the analog-digital converted third harmonic signal are respectively calculated in preset time, and water quality conditions are detected according to the square ratio and the cubic ratio of the voltage amplitude values of the second harmonic and the third harmonic to the excitation voltage amplitude values of the corresponding transmitting transducers;
and displaying the water quality condition in the detection pool.
As described above, the water quality detector and the method thereof have the following beneficial effects:
the method comprises the steps of collecting ultrasonic signals with waveform distortion generated under an uneven water environment in a detection pool, extracting second harmonic waves and third harmonic waves in the ultrasonic signals, respectively calculating voltage amplitude values of the second harmonic waves and the third harmonic waves, and detecting the water quality according to square and third-order ratio results of the voltage amplitude values and excitation voltage amplitude values of a transmitting transducer and a preset threshold range. The water quality detector and the method are simple and easy to operate, meanwhile, compared with other ultrasonic water quality detection modes, the problems of water quality detection precision and efficiency reduction caused by cavitation are solved, and the water quality detector and the method are low in cost and suitable for families.
Drawings
FIG. 1 is a block diagram showing the structure of a water quality detector according to the present invention;
FIGS. 2-a and 2-b are waveform diagrams of ultrasonic waves of a transmitting transducer in the water quality detector according to the present invention;
FIGS. 2-c and 2-d show continuous wave aberration diagrams and impulse wave aberration diagrams of ultrasonic waves emitted by a transducer in the water quality detector of the invention;
FIG. 3 is a block diagram showing the whole structure of the water quality detector of the present invention;
FIG. 4 is a flow chart of a water quality testing method according to the present invention;
FIG. 5 is a detailed flowchart of step S5 in the water quality testing method of the present invention.
Description of element numbers:
1. detection pool
2. Transmitting transducer
3. Receiving transducer
4. Filtering module
5. Controller for controlling a power supply
6. Display device
7. Amplifying circuit
41. Conversion unit
42. Band-pass filter
51. Analog-to-digital conversion unit
52. Calculation unit
53. Detection unit
S1 to S6 Steps 1 to 6
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present invention, which is described by the following specific examples.
Please refer to fig. 1 to 5. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the invention to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the invention, are not intended to be critical to the essential characteristics of the invention, but are intended to fall within the spirit and scope of the invention. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the invention, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the invention may be practiced.
Example 1
Referring to fig. 1, the invention provides a structural block diagram of a water quality detector, which comprises a detection tank 1, a transmitting transducer 2, a receiving transducer 3, a controller 5, a filter circuit and a display 6;
the transmitting transducer 2 is used for inputting an ultrasonic signal generated according to the excitation voltage into the detection cell 1;
wherein the detection tank 1 is also a part of a water quality detector and is used for containing water to be detected, the transmitting transducer 2 generates ultrasonic signals and inputs the ultrasonic signals into the detection tank 1, and the working frequency of the ultrasonic signals is 0.5-20 MHz; the transmitted ultrasonic signal may be classified into a continuous mode or a pulse mode according to whether it is a single frequency, as shown in fig. 2, 2-a is a continuous mode, 2-b is a pulse mode, 2-c is a continuous wave distortion map, and 2-d is a pulse wave distortion map. Both the pulse wave and the continuous wave can carry nonlinear characteristic information due to non-uniformity, except that the amplitude values of their respective harmonics differ, resulting in subsequent threshold parameter settings that may be different.
The receiving transducer 3 is used for collecting ultrasonic signals with waveform distortion generated by the non-uniform water medium in the detection pool, wherein the ultrasonic signals comprise harmonic signals;
the transmitting transducer 2 and the receiving transducer 3 may be installed in the detection cell 1 or installed outside the detection cell 1, and the transmitting transducer 2 and the receiving transducer 3 may be in a transmission mode or a reflection mode. For example, in the case of the perspective mode, the transmitting transducer 2 is in line with the receiving transducer 3, and in the case of the reflection mode, the receiving transducer 3 collects the ultrasonic signal by means of an angular reflection.
In addition, the receiving transducer 3 is preferably a common transducer having high sensitivity at the second harmonic or the third harmonic.
The filtering module 4 is arranged between the receiving transducer 3 and the controller 5 and is used for filtering baseband noise and higher harmonics in each subharmonic signal in the ultrasonic signal to obtain second harmonic voltage signals and third harmonic voltage signals;
the controller 5 is configured to perform analog-to-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal, respectively calculate voltage amplitude values corresponding to the second harmonic signal and the third harmonic signal in a preset time, and detect a water quality condition according to the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the square and the square of the excitation voltage amplitude values of the corresponding transmitting transducers;
wherein, the controller 5 is any one of a central processing unit, a microprocessor, a digital signal processor and a programmable logic device.
The display 6 is connected to the output end of the controller 5 and is used for displaying the water quality condition of the detection tank 1.
The display 6 may be a liquid crystal screen or an LED display screen, so long as the result of the detected water quality condition can be displayed for the user to view.
In this embodiment, the water to be detected is filled in the detection tank 1, wherein the water to be detected is preferably tap water, harmonic signals of ultrasonic waves are collected, second harmonic waves and third harmonic waves in the harmonic signals are extracted, voltage amplitude values of the second harmonic waves and the third harmonic waves are calculated respectively, and the water quality condition is detected according to the ratio results of the voltage amplitude values and square and quadratic of the excitation voltage amplitude values of the transmitting transducer and combining with a preset threshold range. The water quality detector and the method are simple and easy to operate, meanwhile, compared with other ultrasonic water quality detection modes, the problems of water quality detection precision and efficiency reduction caused by cavitation are reduced, and the water quality detector and the method are low in cost and suitable for families.
Detection principle:
in hooke's law of deformation law of reactive materials, there is a high-order term of elastic modulus, and when an ultrasonic signal propagates a certain distance in such uniform materials, a nonlinear effect, called classical nonlinear effect, is generated, and when the ultrasonic intensity is relatively small, the nonlinear effect is generally weak. However, if the material is non-uniform, particularly when the modulus of elasticity of the non-uniform material differs significantly from that of the surrounding medium, even at very low ultrasonic intensities, the propagation of ultrasonic waves in such material will exhibit a much stronger non-linear effect than the uniform material, and the magnitude of the non-linear coefficient of such material can be used to characterize the microstructure of the material. At present, the service life of important parts is evaluated nondestructively by measuring the nonlinear coefficient of a substance in the use process.
Ultrasonic cavitation refers to the dynamic process of growth and collapse that occurs when micro-gas nuclear cavitation bubbles in liquid vibrate under the action of sound waves and sound pressure reaches a certain value.
The water pollution process is that pollutant is dissolved in water, and when the pollutant is dissolved in water, the water adsorbed by the pollutant interface will be dissolved in water together, and very tiny air cavities will be formed between the pollutant and the water. Under the same excitation, the stronger the pollution, the more heterogeneous substances, the greater the pollution formed, the more air pockets in the water, the stronger the odd harmonics (third harmonics) formed. However, the types and properties of pollutants in water are very large, and the second order harmonic is related to the nonlinearity of the heterogeneous substances, so that in order to characterize the pollution condition of the substances in water, the second order harmonic and the third order harmonic are considered in combination, and the condition of water quality is determined according to the voltage amplitude values of the second order harmonic and the third order harmonic which are respectively compared with a threshold value range.
Example 2
FIG. 3 is a block diagram showing the whole structure of the water quality detector according to the present invention; the method specifically comprises the following steps:
the amplifying circuit 7 is arranged between the controller 5 and the transmitting transducer 2 and is used for generating excitation voltage according to a control signal sent by the controller 5 so as to drive the transmitting transducer 2 to work and generate corresponding ultrasonic signals. The amplification circuit 7 preferably uses a PGA202 amplifier model manufactured by the company BURR-BROWN, PGA202 being a programmable instrumentation amplifier having programmable gain change logic integrated therein. Because the gain control part is omitted, the circuit structure can be greatly simplified by constructing the instrument amplifier by using the PGA202, and the amplification factor of the instrument amplifier is stable and accurate, thereby providing convenience for subsequent data processing.
The filtering module 4 comprises a transformation unit 41 and a band-pass filter 42, wherein the transformation unit 41 is used for carrying out wavelet transformation and fast fourier transformation on each subharmonic signal to obtain the fundamental frequency of the harmonic signal, and the wavelet transformation is used for filtering power frequency interference and low frequency interference in the harmonic signal, namely random noise; the fundamental wave amplitude value of the harmonic signal is high in frequency domain, so that the fundamental wave amplitude value of the harmonic signal is easy to distinguish, and the signal subjected to wavelet transformation is subjected to fast Fourier transformation to determine the fundamental wave frequency of the harmonic signal; the bandpass filter 42 includes a second harmonic bandpass filter 42 and a third harmonic bandpass filter 42, and the frequencies of the second harmonic and the third harmonic depend on the fundamental frequency of the transmitting transducer 2. When the fundamental frequency is known, the frequencies of the second harmonic band-pass filter 42 and the third harmonic band-pass filter 42 can be set correspondingly, so that the influence of the subharmonic signals is reduced.
The controller 5 comprises at least the following three units:
the analog-to-digital conversion unit 51 is configured to perform analog-to-digital conversion on the second harmonic signal and the third harmonic voltage signal, respectively, to generate a corresponding second harmonic digital signal and a third harmonic digital signal; the analog-to-digital conversion unit 51 may be an analog-to-digital converter.
The calculating unit 52 is configured to calculate a second harmonic voltage amplitude value and a third harmonic voltage amplitude value corresponding to the second harmonic digital signal and the third harmonic digital signal respectively in a preset time;
before the measurement of the water quality detector, the thresholds of C1 and C2 are preset according to the water quality standard, and in the preset time, when the thresholds of C1 and C2 are exceeded, the pollution is considered serious, and when the thresholds are lower than a certain threshold, the middle pollution is considered to be middle pollution. The preset time is a time period set by the user, and is preferably 2 seconds generally.
The detecting unit 53 is configured to detect a water quality condition in the detection tank by comparing a measured ratio result with a preset threshold according to a ratio of the square of the second harmonic voltage amplitude value and the excitation voltage amplitude value of the corresponding transmitting transducer and a ratio of the third harmonic voltage amplitude value and the third power of the excitation voltage amplitude value of the corresponding transmitting transducer,
C1＝A 2X /V 2 (1)
C2＝A 3X /V 3 (2)
in the formulas (1) and (2), V is the excitation voltage amplitude value of the transmitting transducer, A 2x Is the amplitude value of the second harmonic voltage, A 3x And C1 and C2 are square and cubic ratio of the amplitude value of the third harmonic voltage and the amplitude value of the exciting voltage of the transmitting transducer respectively.
For example, according to the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the excitation voltage of the corresponding transmitting transducer, the threshold values are distributed in a stepwise manner according to the preset threshold ranges of C1 and C2, and can be classified according to the quality of water quality, such as "good", "safe", "careful", "dangerous", etc., when they exceed their respective highest threshold values, the water quality is displayed as "dangerous", when they are below their lowest threshold values, the water quality is displayed as "good", and according to the water quality conditions detected when the threshold ranges of C1 and C2 fall.
In the example, when a user uses the system to detect the water quality, the corresponding water quality detection result can be obtained by only filling water into the detection tank 1 and starting the detection system, no operation is needed in the middle, and the system is simple and convenient; meanwhile, by detecting the harmonic signals as the detection standard of the quality degree of the water quality, compared with other detectors for detecting the water quality by utilizing ultrasonic waves, the problems of detection accuracy and efficiency reduction due to the phenomenon of empty words are reduced; when a user needs to detect different water qualities for a plurality of times, distilled water is preferably used for cleaning the detection tank 1 so as not to affect the detection accuracy.
Example 3
As shown in fig. 4, a flow chart of a water quality detection method according to the present invention includes:
step S1, introducing water to be detected into a detection pool;
specifically, the water to be measured is preferably tap water;
s2, under the excitation voltage, transmitting an ultrasonic signal into the detection pool;
specifically, a control signal is sent to an amplifying circuit to generate excitation voltage so as to drive a transmitting transducer to work and generate an ultrasonic signal;
s3, collecting ultrasonic signals with waveform distortion generated by a non-uniform water medium in a detection pool by a receiving transducer, wherein the ultrasonic signals comprise harmonic signals;
specifically, the ultrasonic signals collected by the receiving transducer contain various harmonic signals such as fundamental harmonic signals, secondary harmonic signals, tertiary harmonic signals and the like through waveform distortion;
step S4, filtering out baseband noise and higher harmonics in each subharmonic signal in the ultrasonic signal to obtain second and third harmonic voltage signals;
the harmonic signal is subjected to wavelet transformation and fast Fourier transformation to obtain fundamental wave frequency of the harmonic signal, and a second harmonic band-pass filter and a third harmonic band-pass filter are respectively adopted according to the fundamental wave frequency to obtain corresponding second harmonic voltage signal and third harmonic voltage signal.
S5, carrying out analog-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal, respectively calculating voltage amplitude values corresponding to the analog-digital converted second harmonic signal and the analog-digital converted third harmonic signal in preset time, and detecting water quality according to square and cubic ratio values of the voltage amplitude values of the second harmonic and the third harmonic and excitation voltage amplitude values of the corresponding transmitting transducers;
and S6, displaying the water quality condition in the detection pool.
As shown in fig. 5, the detailed flowchart of step S5 in the water quality detection method includes:
step S501, respectively performing analog-digital conversion on the second harmonic signal and the third harmonic voltage signal to generate a corresponding second harmonic digital signal and a corresponding third harmonic digital signal;
step S502, respectively calculating a second harmonic voltage amplitude value and a third harmonic voltage amplitude value corresponding to the second harmonic digital signal and the third harmonic digital signal in preset time;
step S503, according to the ratio of the square of the second harmonic voltage amplitude value and the excitation voltage amplitude value of the corresponding transmitting transducer and the ratio of the third harmonic voltage amplitude value and the square of the excitation voltage amplitude value of the corresponding transmitting transducer, comparing the measured ratio result with a preset threshold value to detect the water quality condition in the detection pool.
The square and third-order ratio of the voltage amplitude values of the second harmonic and the third harmonic to the excitation voltage amplitude value of the corresponding transmitting transducer is calculated according to the following formula:
C1＝A 2X /V 2 (1)
C2＝A 3X /V 3 (2)
in the formulas (1) and (2), V is the excitation voltage amplitude value of the transmitting transducer, A 2x For the amplitude of the second harmonic voltage, A 3x And C1 and C2 are respectively square and cubic ratio of the amplitude value of the third harmonic voltage and the amplitude value of the excitation voltage of the transmitting transducer.
In summary, the invention extracts the second harmonic and the third harmonic from the harmonic signals by collecting the harmonic signals of the ultrasonic waves, calculates the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the square and the third square of the excitation voltage of the transmitting transducer, and detects the water quality according to the ratio result. The water quality detector and the method are simple and easy to operate, meanwhile, compared with other ultrasonic water quality detection modes, the problems of water quality detection precision and efficiency reduction caused by cavitation are avoided, and the water quality detector and the method are low in cost and suitable for families. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (8)
1. The water quality detector is characterized by comprising a detection pool, a transmitting transducer, a receiving transducer, a controller, a filtering module and a display;
the transmitting transducer is used for inputting ultrasonic signals generated according to the excitation voltage into the detection pool;
the receiving transducer is used for collecting ultrasonic signals with waveform distortion generated by the non-uniform water medium in the detection pool, wherein the ultrasonic signals comprise harmonic signals;
the filtering module is arranged between the receiving transducer and the controller and is used for filtering baseband noise and higher harmonics in each subharmonic signal to obtain second and third harmonic voltage signals; the filtering module comprises a transformation unit and a band-pass filter, wherein the transformation unit is used for carrying out wavelet transformation and fast Fourier transformation on each subharmonic signal to obtain the fundamental frequency of the harmonic signal, the band-pass filter comprises a second harmonic band-pass filter and a third harmonic band-pass filter, and the frequencies of the second harmonic and the third harmonic are determined according to the fundamental frequency of the transmitting transducer;
the controller is used for carrying out analog-to-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal, respectively calculating voltage amplitude values corresponding to the second harmonic voltage signal and the third harmonic voltage signal in preset time, and detecting water quality conditions according to the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the square and the third square of the excitation voltage amplitude value of the transmitting transducer;
the amplifying circuit is arranged between the controller and the transmitting transducer and is used for generating excitation voltage according to a control signal sent by the controller so as to drive the transmitting transducer to work;
the display is connected to the output end of the controller and used for displaying the water quality condition of the detection pool.
2. The water quality detector of claim 1, wherein the controller further comprises an analog-to-digital conversion unit, a calculation unit, and a detection unit;
the analog-to-digital conversion unit is used for respectively carrying out analog-to-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal to generate corresponding second harmonic digital signals and third harmonic digital signals;
the calculating unit is used for respectively calculating the second harmonic voltage amplitude value and the third harmonic voltage amplitude value corresponding to the second harmonic digital signal and the third harmonic digital signal in preset time;
the detection unit is used for comparing the measured respective ratios with a preset threshold value to detect the water quality condition in the detection pool according to the square ratio of the second harmonic voltage amplitude value to the excitation voltage amplitude value of the transmitting transducer and the cubic ratio of the third harmonic voltage amplitude value to the excitation voltage amplitude value of the transmitting transducer.
3. The water quality detector according to claim 2, wherein the detecting unit calculates the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the square and the third square of the excitation voltage amplitude value of the corresponding transmitting transducer according to the following formula:
C1＝A 2X /V 2 (1)
C2 ＝A 3X /V 3 (2)
in the formulas (1) and (2), V is the excitation voltage amplitude value of the transmitting transducer, A 2x Is the amplitude value of the second harmonic voltage, A 3x And C1 and C2 are square and cubic ratio of the amplitude value of the third harmonic voltage and the amplitude value of the exciting voltage of the transmitting transducer respectively.
4. A method for water quality testing comprising:
introducing water to be detected into a detection pool;
transmitting ultrasonic signals into the detection cell under the excitation voltage;
the method comprises the steps that a receiving transducer collects ultrasonic signals with waveform distortion generated by a non-uniform water medium in a detection pool, wherein the ultrasonic signals comprise subharmonic signals;
filtering baseband noise and higher harmonics in each subharmonic signal in the ultrasonic signal to obtain a second harmonic voltage signal and a third harmonic voltage signal;
performing analog-to-digital conversion on the second harmonic voltage signal and the third harmonic voltage signal, respectively calculating voltage amplitude values corresponding to the analog-to-digital converted second harmonic signal and the third harmonic signal in preset time, and detecting water quality according to the ratio of the voltage amplitude values of the second harmonic and the third harmonic to the square and the third square of the excitation voltage amplitude values of the corresponding transmitting transducers;
and displaying the water quality condition in the detection pool.
5. The method of water quality testing according to claim 4, wherein the step of filtering out the baseband noise and higher harmonics in each subharmonic signal in the ultrasonic signal to obtain second and third harmonic voltage signals comprises:
wavelet transformation and fast Fourier transformation are carried out on each subharmonic signal in the ultrasonic signal so as to obtain the fundamental frequency of the harmonic signal, and a second harmonic band-pass filter and a third harmonic band-pass filter are respectively adopted to obtain corresponding second harmonic voltage signals and third harmonic voltage signals.
6. The method of water quality detection according to claim 4, wherein the step of performing analog-to-digital conversion on the second and third harmonic voltage signals, respectively calculating voltage amplitude values corresponding to the analog-to-digital converted second and third harmonic signals in a preset time, and detecting water quality according to square and third aspect ratios of the voltage amplitude values of the second and third harmonics and the corresponding excitation voltage amplitude values respectively comprises:
analog-to-digital conversion is carried out on the second harmonic signal and the third harmonic voltage signal respectively, so as to generate a corresponding second harmonic digital signal and a corresponding third harmonic digital signal;
respectively calculating a second harmonic voltage amplitude value and a third harmonic voltage amplitude value corresponding to the second harmonic digital signal and the third harmonic digital signal in preset time;
and comparing the measured ratio result with a preset threshold value to detect the water quality condition in the detection pool according to the square ratio of the second harmonic voltage amplitude value and the corresponding excitation voltage amplitude value and the square ratio of the third harmonic voltage amplitude value and the corresponding excitation voltage amplitude value.
7. The method of water quality testing according to claim 4, wherein the step of determining the ratio of the square of the second harmonic voltage amplitude value and the excitation voltage amplitude value of the corresponding transmitting transducer to the ratio of the third harmonic voltage amplitude value and the square of the excitation voltage amplitude value of the corresponding transmitting transducer comprises:
the square and third-order ratio of the voltage amplitude values of the second harmonic and the third harmonic to the excitation voltage amplitude value of the corresponding transmitting transducer is calculated according to the following formula:
C1＝A 2X /V 2 (1)
C2 ＝A 3X /V 3 (2)
in the formulas (1) and (2), V is the excitation voltage amplitude value of the transmitting transducer, A 2x For the amplitude of the second harmonic voltage, A 3x The amplitude of the third harmonic voltage is respectively C1 and C2, which are the square of the amplitude of the second harmonic voltage and the amplitude of the exciting voltage of the transmitting transducer,The ratio of the power of three.
8. The method of water quality testing according to claim 4, wherein the step of transmitting an ultrasonic signal into the test cell at the excitation voltage comprises: and sending a control signal to the amplifying circuit to generate an excitation voltage so as to drive the transmitting transducer to work.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610507308.4A CN107561157B (en) | 2016-06-30 | 2016-06-30 | Water quality detector and method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610507308.4A CN107561157B (en) | 2016-06-30 | 2016-06-30 | Water quality detector and method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107561157A CN107561157A (en) | 2018-01-09 |
| CN107561157B true CN107561157B (en) | 2023-08-04 |
Family
ID=60968925
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610507308.4A Active CN107561157B (en) | 2016-06-30 | 2016-06-30 | Water quality detector and method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107561157B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108303357B (en) * | 2018-01-29 | 2021-02-05 | 杭州开闳环境科技有限公司 | Suspended load measurement system based on multi-frequency underwater acoustic signals and signal processing method |
| CN110146595B (en) * | 2019-04-23 | 2023-07-14 | 宁波水表股份有限公司 | Water turbidity measuring method based on ultrasonic waves |
| CN112414906B (en) * | 2020-10-22 | 2023-02-14 | 北京北方华创微电子装备有限公司 | Detection device for concentration of particulate matter in liquid medicine and liquid change control method |
| CN114384155A (en) * | 2022-01-12 | 2022-04-22 | 重庆医科大学 | Measuring system and method for measuring sound velocity of medium in waveguide |
Citations (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993003340A1 (en) * | 1991-07-29 | 1993-02-18 | Kay-Ray/Sensall, Inc. | Time gate ultrasonic sensor and method |
| US5302878A (en) * | 1991-10-30 | 1994-04-12 | Imaje S.A. | High-frequency acoustic rheometer and device to measure the viscosity of a fluid using this rheometer |
| JPH06174700A (en) * | 1992-12-09 | 1994-06-24 | Mitsubishi Heavy Ind Ltd | Apparatus and method for measuring constituent concentration |
| US5523058A (en) * | 1992-09-16 | 1996-06-04 | Hitachi, Ltd. | Ultrasonic irradiation apparatus and processing apparatus based thereon |
| JPH10179589A (en) * | 1996-11-08 | 1998-07-07 | Atl Ultrasound Inc | Ultrasonic image processing method and device by higher harmonic wave |
| JP2001008933A (en) * | 1999-07-01 | 2001-01-16 | Matsushita Electric Ind Co Ltd | Ultrasonic transmitting and receiving method and ultrasonograph |
| JP2003265466A (en) * | 2002-03-12 | 2003-09-24 | Olympus Optical Co Ltd | Ultrasonograph |
| JP2003287525A (en) * | 2002-03-27 | 2003-10-10 | Toshiba Corp | Water-quality monitoring apparatus |
| JP2006284428A (en) * | 2005-04-01 | 2006-10-19 | Nippon Steel Corp | Method and device for detecting inclusion with nonlinear ultrasonic wave |
| CN1912612A (en) * | 2006-08-15 | 2007-02-14 | 天津工业大学 | Detection method and device of multi-phase matter |
| CN101530320A (en) * | 2009-03-31 | 2009-09-16 | 西安交通大学 | Real-time extracting device and detection method for focused ultrasonic cavitation and microbubbles thereof |
| CN101982156A (en) * | 2010-09-08 | 2011-03-02 | 北京航空航天大学 | Blood-pressure noninvasive measuring device based on micro-bubble ultrasound contrast agents and measuring method thereof |
| WO2012004113A1 (en) * | 2010-07-08 | 2012-01-12 | Endress+Hauser Flowtec Ag | Ultrasonic particle measuring system |
| CN102488532A (en) * | 2011-12-12 | 2012-06-13 | 南京大学 | Peripheral static pressure measurement method based on micro-vesicle super-harmonic response |
| WO2013055207A1 (en) * | 2011-10-10 | 2013-04-18 | Lg Sound B.V. | A system and method for predicting,monitoring, preventing and controlling algae in open water |
| JP2014027730A (en) * | 2012-07-25 | 2014-02-06 | Sharp Corp | Control device |
| JP2014196996A (en) * | 2013-03-08 | 2014-10-16 | 三菱電機株式会社 | Liquid detection method and liquid detection device |
| RU2532143C1 (en) * | 2013-07-03 | 2014-10-27 | Федеральное государственное бюджетное учреждение науки Тихоокеанский океанологический институт им. В.И. Ильичева Дальневосточного отделения Российской академии наук (ТОИ ДВО РАН) | Method of determination of nonlinear ultrasonic parameter of liquids and device for its implementation |
| CN104764522A (en) * | 2015-04-08 | 2015-07-08 | 重庆医科大学 | Ultrasonic power measurement method and device |
| CN204694345U (en) * | 2015-06-19 | 2015-10-07 | 重庆医科大学 | A kind of ultrasonic power measuring device |
| WO2015155320A1 (en) * | 2014-04-11 | 2015-10-15 | Universite De Tours Francois-Rabelais | Method for controlling cmut transducers in harmonic ultrasound, particularly in contrast harmonic ultrasound |
| CN205941458U (en) * | 2016-06-30 | 2017-02-08 | 重庆医科大学 | Water quality detector |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060086604A1 (en) * | 1996-09-24 | 2006-04-27 | Puskas William L | Organism inactivation method and system |
| US6896658B2 (en) * | 2001-10-20 | 2005-05-24 | Zonare Medical Systems, Inc. | Simultaneous multi-mode and multi-band ultrasonic imaging |
| GB2384310A (en) * | 2002-01-19 | 2003-07-23 | Stichting Tech Wetenschapp | Ultrasonic tissue imaging using high order harmonics |
| US7018546B2 (en) * | 2003-03-06 | 2006-03-28 | Hitachi, Ltd. | Water treatment method and water treatment device |
| US8176783B2 (en) * | 2007-09-25 | 2012-05-15 | Los Alamos National Security, Llc | Non-contact fluid characterization in containers using ultrasonic waves |
| KR20090116040A (en) * | 2008-05-06 | 2009-11-11 | 한국표준과학연구원 | Pressure measuring apparatus inside a vessel using acoustic impedance matching layers |
| US20100147080A1 (en) * | 2008-12-16 | 2010-06-17 | General Electric Company | Ultrasonic transducer |
| JP6189227B2 (en) * | 2013-02-20 | 2017-08-30 | 株式会社東芝 | Ultrasonic flaw detector and its evaluation method |
-
2016
- 2016-06-30 CN CN201610507308.4A patent/CN107561157B/en active Active
Patent Citations (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993003340A1 (en) * | 1991-07-29 | 1993-02-18 | Kay-Ray/Sensall, Inc. | Time gate ultrasonic sensor and method |
| US5302878A (en) * | 1991-10-30 | 1994-04-12 | Imaje S.A. | High-frequency acoustic rheometer and device to measure the viscosity of a fluid using this rheometer |
| US5523058A (en) * | 1992-09-16 | 1996-06-04 | Hitachi, Ltd. | Ultrasonic irradiation apparatus and processing apparatus based thereon |
| JPH06174700A (en) * | 1992-12-09 | 1994-06-24 | Mitsubishi Heavy Ind Ltd | Apparatus and method for measuring constituent concentration |
| JPH10179589A (en) * | 1996-11-08 | 1998-07-07 | Atl Ultrasound Inc | Ultrasonic image processing method and device by higher harmonic wave |
| JP2001008933A (en) * | 1999-07-01 | 2001-01-16 | Matsushita Electric Ind Co Ltd | Ultrasonic transmitting and receiving method and ultrasonograph |
| JP2003265466A (en) * | 2002-03-12 | 2003-09-24 | Olympus Optical Co Ltd | Ultrasonograph |
| JP2003287525A (en) * | 2002-03-27 | 2003-10-10 | Toshiba Corp | Water-quality monitoring apparatus |
| JP2006284428A (en) * | 2005-04-01 | 2006-10-19 | Nippon Steel Corp | Method and device for detecting inclusion with nonlinear ultrasonic wave |
| CN1912612A (en) * | 2006-08-15 | 2007-02-14 | 天津工业大学 | Detection method and device of multi-phase matter |
| CN101530320A (en) * | 2009-03-31 | 2009-09-16 | 西安交通大学 | Real-time extracting device and detection method for focused ultrasonic cavitation and microbubbles thereof |
| WO2012004113A1 (en) * | 2010-07-08 | 2012-01-12 | Endress+Hauser Flowtec Ag | Ultrasonic particle measuring system |
| CN101982156A (en) * | 2010-09-08 | 2011-03-02 | 北京航空航天大学 | Blood-pressure noninvasive measuring device based on micro-bubble ultrasound contrast agents and measuring method thereof |
| WO2013055207A1 (en) * | 2011-10-10 | 2013-04-18 | Lg Sound B.V. | A system and method for predicting,monitoring, preventing and controlling algae in open water |
| CN102488532A (en) * | 2011-12-12 | 2012-06-13 | 南京大学 | Peripheral static pressure measurement method based on micro-vesicle super-harmonic response |
| JP2014027730A (en) * | 2012-07-25 | 2014-02-06 | Sharp Corp | Control device |
| JP2014196996A (en) * | 2013-03-08 | 2014-10-16 | 三菱電機株式会社 | Liquid detection method and liquid detection device |
| RU2532143C1 (en) * | 2013-07-03 | 2014-10-27 | Федеральное государственное бюджетное учреждение науки Тихоокеанский океанологический институт им. В.И. Ильичева Дальневосточного отделения Российской академии наук (ТОИ ДВО РАН) | Method of determination of nonlinear ultrasonic parameter of liquids and device for its implementation |
| WO2015155320A1 (en) * | 2014-04-11 | 2015-10-15 | Universite De Tours Francois-Rabelais | Method for controlling cmut transducers in harmonic ultrasound, particularly in contrast harmonic ultrasound |
| CN104764522A (en) * | 2015-04-08 | 2015-07-08 | 重庆医科大学 | Ultrasonic power measurement method and device |
| CN204694345U (en) * | 2015-06-19 | 2015-10-07 | 重庆医科大学 | A kind of ultrasonic power measuring device |
| CN205941458U (en) * | 2016-06-30 | 2017-02-08 | 重庆医科大学 | Water quality detector |
Non-Patent Citations (1)
| Title |
|---|
| 超声辅助Fenton试剂消解-光谱分析法快速测定水质总磷;魏康林;光谱学与光谱分析;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107561157A (en) | 2018-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107561157B (en) | Water quality detector and method thereof | |
| CN204389475U (en) | A kind of multi-parameter water quality on-line monitoring device | |
| Azman et al. | A low cost nephelometric turbidity sensor for continual domestic water quality monitoring system | |
| CN104697917B (en) | The impedance bioelectrical measurement system anomaly detection method and system combined based on multiple features | |
| JP2016048185A (en) | Method and device for measuring bubble diameter distribution | |
| CN205941458U (en) | Water quality detector | |
| CN201740731U (en) | Online ozone monitor | |
| Sarno et al. | An objective comparison of commercially-available cavitation meters | |
| Vian et al. | Cluster collapse in a cylindrical cell: correlating multibubble sonoluminescence, acoustic pressure, and erosion | |
| US11898949B2 (en) | Fine bubble elimination method and fine bubble elimination device, and bubble size distribution measuring method and bubble size distribution measuring device | |
| Moura et al. | Field observations of SPM using ADV, ADP, and OBS in a shallow estuarine system with low SPM concentration—Vitória Bay, SE Brazil | |
| JP6264229B2 (en) | Bubble diameter distribution measuring method and bubble diameter distribution measuring apparatus | |
| CN205103129U (en) | Novel particulate matter sensor | |
| CN204154642U (en) | A kind of infrared oil smoke concentration sensor | |
| Rodriguez-Molares et al. | Determination of biomass concentration by measurement of ultrasonic attenuation | |
| CN206248598U (en) | A kind of equipment of smoke dust sampling | |
| Wiranto et al. | Design and realisation of a turbidimeter using TSL250 photodetector and Arduino microcontroller | |
| CN201440122U (en) | Laser turbidity meter | |
| CN206348321U (en) | A kind of Portable smoke analysis instrument | |
| CN103398981A (en) | Method for detecting drainage oil | |
| CN203606258U (en) | Simple tester for particulate matter (PM)2.5 content in air | |
| Pohrebennyk et al. | Operative control parameters of water environment | |
| CN106442717A (en) | Surface acoustic wave transducer for detecting volatile organic pollutants | |
| CN111175203B (en) | Detection system for ultralow dust on-line monitoring | |
| Mahajan et al. | An IoT based system for water quality monitoring |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |