Liquid detection method and system based on measurement of surface capillary waves with structured light

Abstract

The invention provides a liquid detection method and a system based on measurement of surface capillary waves with structured light. The liquid detection method comprises steps of generating surface waves of liquid to be measured and projecting the predetermined structured light onto the surface of the liquid to be measured; analyzing actual height change represented by stripes of the surface waves of the liquid to be measured to obtain a wavelength of the surface capillary waves of the liquid to be measured; calculating surface tension of the liquid to be measured based on the wavelength of the surface capillary waves, and obtaining a type of the liquid to be measured according to an established relationship between the liquid type and the surface tension of the liquid. The method and thesystem of the present invention use the characteristics of surface capillary waves of the liquid to propose a high-precision, low-cost, and universal detection mechanism.

Description

technical field [0001] The invention relates to the technical field of liquid detection, in particular to a liquid detection method and system for measuring surface capillary waves based on structured light. Background technique [0002] For safety reasons, dangerous liquid detection is essential in various public transportation places such as subways and airports; moreover, people now pay more attention to diet, and there are more and more demands for analyzing food components and calories, but the existing liquids used The detection equipment is very expensive, so on the basis of realizing the detection of substances and the identification of liquid concentration and liquid level, it is also very important to make a cheap and portable liquid detection meter, which has gradually become a research hotspot. [0003] At present, there are mainly several types of dangerous liquid detection used in security inspection. The first is to use Raman spectroscopy, which can use a hand...

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Problems solved by technology

[0002] For safety reasons, dangerous liquid detection is essential in various public transportation places such as subways and airports; moreover, people now pay more attention to diet, and there are more and more demands for analyzing food components and calories, but the existing liquids used The detection equipment is very expensive, so on the basis of realizing the detection of substances and the identification of liquid concentration and liquid level, it is also very important to make a cheap and portable liquid detector, which has gradually become a research hotspot.

[0003] At present, there are mainly several types of dangerous liquid detection used in security inspection. The first is to use Raman spectroscopy, which can use a handheld device to emit a beam of laser light, and then use the reflected light to analyze the spectral differences of different substances to distinguish liquid components. , but the disadvantage is that the price is very expensive; the second is the fluorescence quenching technology, which is a sensing material specially prepared for common dangerous substances, but the instruments used in these methods are very expensive, and they cannot detect containers other than plastic bottles; The third method is the dielectric constant method. This method is relatively cheap and the equipment is small, but the accuracy is not high. This method transmits an electrical signal through the transmitting antenna, and the nearby receiving antenna receives the returned electrical signal, and analyzes the electrical conductivity from the received signal. Rate to calculate the dielectric constant to classify the liquid

Since it is not only necessary to detect liquids in security checks, but also to detect drinking beverages and water quality when going out, portable and cheap detectors are required. It is not ideal to use these professional but cumbersome devices.

[0004] The existing common water quality detection is to use infrared light to judge the turbidity of the liquid by measuring the light transmittance and scattering rate in the solution. The more turbid the water is, the less light is transmitted, but this method can only detect the turbidity of the water , but it cannot detect other types of liquids, because different types of liquids absorb the emitted infrared light differently, and it is very one-sided to analyze liquids from the received infrared light

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