CN112985549A

CN112985549A - Mass measurement method based on acoustic resonance

Info

Publication number: CN112985549A
Application number: CN202110199211.2A
Authority: CN
Inventors: 史依晨
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-02-22
Filing date: 2021-02-22
Publication date: 2021-06-18
Anticipated expiration: 2041-02-22
Also published as: CN112985549B

Abstract

The invention provides a mass measurement method based on acoustic resonance, which comprises the following steps: adjusting a light path to enable light beams emitted by the light source to form light spots on the screen after being reflected by the reflecting film; controlling a sound source to send sound waves with different frequencies to the vibrating diaphragm, and observing the change of light spots to measure to obtain the resonant frequency of the vibrating diaphragm; fixing an object with known mass on the surface of the diaphragm; controlling a sound source to emit sound waves with different frequencies to the vibrating diaphragm, and measuring the resonant frequency of a first combination of an object with known mass and the vibrating diaphragm by observing the change of light spots; removing an object with known mass from the surface of the vibrating diaphragm, and fixing a sample to be detected on the surface of the vibrating diaphragm; controlling a sound source to emit sound waves with different frequencies to the vibrating diaphragm, and measuring the resonance frequency of the sample to be measured and the second assembly of the vibrating diaphragm by observing the change of the light spots; and comparing the resonance frequency of the first combination with the resonance frequency of the second combination to obtain the quality of the sample to be detected. The invention can solve the technical problems of low measurement precision of a mechanical balance and high measurement cost of an electronic balance when an object is subjected to mass measurement.

Description

Mass measurement method based on acoustic resonance

Technical Field

The invention relates to the technical field of quality measurement, in particular to a quality measurement method based on acoustic resonance.

Background

The method has wide requirements for high-precision measurement of the quality of the object in the fields of daily life, industrial measurement, scientific research and the like. At present, when measuring the mass of an object, a balance is mainly used to perform the measurement, and the balance can be classified into a mechanical balance and an electronic balance.

Mechanical balances have the disadvantage of low measurement accuracy, typically 0.1g, and require the use of electronic balances to achieve high-accuracy mass measurements. Although the electronic balance can reach higher precision (0.01-0.001g), the electronic balance has higher purchase cost, and has higher requirements on the temperature and the humidity of the use environment, generally, the environment temperature is required to be 23 +/-3 ℃, the environment humidity is required to be 45-75% RH, the use environment of the electronic balance is regulated to the specified temperature and humidity, extra environmental regulation cost is required to be invested, and the purchase cost of the electronic balance is added, so that higher measurement cost is formed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a mass measurement method based on acoustic resonance, and aims to solve the technical problems that when an object is subjected to mass measurement in the prior art, the mechanical balance is low in measurement precision, and the electronic balance is high in measurement cost.

The invention adopts the technical scheme that the mass measurement method based on the acoustic wave resonance comprises the following steps in a first realization mode:

adjusting a light path to enable light beams emitted by the light source to form light spots on the screen after being reflected by the reflecting film;

controlling a sound source to send sound waves with different frequencies to the vibrating diaphragm, and observing the change of light spots to measure to obtain the resonant frequency of the vibrating diaphragm;

fixing an object with known mass on the surface of the diaphragm;

controlling a sound source to emit sound waves with different frequencies to the vibrating diaphragm, and measuring the resonant frequency of a first combination of an object with known mass and the vibrating diaphragm by observing the change of light spots;

removing an object with known mass from the surface of the vibrating diaphragm, and fixing a sample to be detected on the surface of the vibrating diaphragm;

controlling a sound source to emit sound waves with different frequencies to the vibrating diaphragm, and measuring the resonance frequency of a second combination of the sample to be measured and the vibrating diaphragm by observing the change of the light spots;

and comparing the first combination resonance frequency with the first combination resonance frequency to obtain the quality of the sample to be detected. The beneficial technical effects of the technical scheme are as follows: by utilizing the principle that the resonance frequency of an object has correlation with the mass of the object, as the change of the resonance frequency has high sensitivity to the change of the mass of the object, the high measurement precision can be obtained by selecting the proper film size and thickness, and the measurement precision can reach 0.001g, which is more than a mechanical balance and is equivalent to an electronic balance.

With reference to the first implementable manner, in a second implementable manner, before measurement, the measurement device is arranged as follows:

placing a sound source in the cup body;

fixing the reflecting film on the surface of the sealing film, and arranging an adhesive area beside the reflecting film and on the surface of the sealing film;

sealing the opening of the cup body by using a sealing film;

and connecting the sound source through the control terminal.

With reference to the first implementable manner, in a third implementable manner, the measuring device further includes a support and an image acquisition device;

the bracket is positioned beside the cup body, and the light source and the image acquisition equipment are arranged on the bracket;

and the image acquisition equipment acquires images of the light spots and transmits the acquired images to the terminal equipment.

With reference to the third implementable manner, in a fourth implementable manner, the method is characterized in that: the image acquisition equipment is a camera, and the terminal equipment is a smart phone. The beneficial technical effects of the technical scheme are as follows: people can control the Bluetooth sound box on the smart phone simultaneously, and observe the change condition of light spots, and the operation is more convenient.

In combination with the first implementable manner, in the fifth implementable manner, coordinates are set on the screen, and the spot change is observed in combination with the coordinates to obtain the maximum size in the spot change process.

In combination with the fifth implementable manner, in the sixth implementable manner, the grid coordinate paper is used to set the coordinates on the screen.

In combination with the sixth implementation manner, in the seventh implementation manner, when the sound source is controlled to emit sound waves with different frequencies to the diaphragm, the sweep frequency is stepped to 1Hz or 0.1 Hz. The beneficial technical effects of the technical scheme are as follows: when people observe the change of light spots, the vertical coordinate and the horizontal coordinate on the check coordinate paper are used as references, so that the visual deviation of the size caused by visual observation can be avoided. Meanwhile, when the sound wave frequency emitted by the Bluetooth sound box is controlled, the frequency sweeping is carried out step by step according to the frequency sweeping frequency of 0.1Hz, so that more accurate resonance frequency can be obtained, and the precision of quality measurement is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic view showing the arrangement of a measuring apparatus according to example 1 of the present invention;

FIG. 2 is a flowchart of a measurement method according to embodiment 1 of the present invention;

FIG. 3 is a schematic diagram showing changes in resonance frequency and spot size in example 1 of the present invention;

FIG. 4 is a schematic view of the arrangement of a measuring apparatus in example 2 of the present invention;

FIG. 5 is a graph showing the effect of observing the change in spot size on coordinate paper in example 3 of the present invention;

reference numerals:

1-cup body, 2-sound source, 3-sealing film, 4-reflecting film, 5-bonding area, 6-light source, 7-screen, 8-light spot, 9-bracket and 10-image acquisition equipment.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

Example 1

The embodiment provides a mass measurement method based on acoustic wave resonance, which comprises the following steps:

fixing an object with known mass on the surface of the diaphragm;

and comparing the resonance frequency of the first combination with the resonance frequency of the second combination to obtain the quality of the sample to be detected.

The working principle of example 1 is explained in detail below:

to implement the quality measurement method of the present embodiment, as shown in fig. 1, the following measurement devices are used:

(1) cup body

The shape and material of the cup body 1 are not limited, but for example, in the specific embodiment: the cup body 1 can be a water cup or a vase for daily drinking; the shape is cylindrical or pear-shaped, and the material is glass, ceramic, metal or plastic. The cup body 1 is provided with a cavity and an opening communicated with the cavity.

In the present embodiment, the cup body 1 is preferably a cylindrical ceramic cup.

(2) Sound source

The sound source 2 is arranged inside the cavity of the cup body 1 and used for emitting sound waves with different frequencies. The implementation of the sound source 2 is not limited, and for example, in a specific embodiment: sound source 2 optional is less than the bluetooth speaker or the WIFI audio amplifier of cup opening diameter with whole size to make sound source 2 can put into the cup. Bluetooth audio amplifier or WIFI audio amplifier have the wireless communication function, can use the APP of smart mobile phone (such as Frequency Sound Generator) to carry out remote operation to the audio amplifier, control opening, closing of audio amplifier to and send the Sound wave of different frequencies.

In this embodiment, preferably, the sound source 2 is a millet mini bluetooth speaker.

(3) Vibrating diaphragm

The diaphragm comprises a sealing film 3 and a reflecting film 4.

The sealing film 3 is used for sealing the opening of the cup body 1, and the film body of the sealing film 3 is in a tight state after the opening is sealed. The thickness and material of the sealing film 3 are not limited, but are exemplified by: the sealing film 3 can be selected from latex film, fiber film, and plastic film, and has a thickness of 5-100 μm. The manner of sealing the cup opening is not limited, and in particular embodiments, by way of example: the sealing film 3 is stuck on the opening edge of the cup body 1 in a sticking way to seal the opening of the cup body. In this embodiment, the sealing film 3 is preferably a food preservative film.

The reflection film 4 is fixed to the upper surface of the seal film 3. The material and size of the reflective film 4 are not limited, but are exemplified by the following specific embodiments: the reflecting film 4 can be a reflecting coating, a reflecting film and a tin foil paper, the length and the width are 10 multiplied by 10 to 20 multiplied by 20mm, and the thickness is 10 to 30 mu m. The fixing manner and the fixing position of the reflective film 4 are not limited, and for example, in a specific embodiment: the reflecting film 4 is fixed on the upper surface of the sealing film 3, the central position of the cup opening or the side of the central position in a sticking way. In this embodiment, the reflective film 4 is preferably made of tin foil paper and fixed beside the center of the opening of the cup.

To facilitate subsequent fixing of objects, including objects of known quality and samples to be tested, on the sealing film 3, an adhesive region 5 is provided on the sealing film 3 in a region other than the reflective film 4. The realization of the adhesive area 5 is not limited, by way of example, in a particular embodiment: the adhesive area 5 can be formed by gluing part of the sealing film 3 or by gluing part of the sealing film 3 with a double-sided adhesive tape; the adhesive area 5 may be one or more. In this embodiment, a circular double-sided tape is preferably attached to the side of the foil paper at the middle position of the upper surface of the sealing film 3 to form an adhesive area. The double-sided adhesive tape can stick objects, is not too strong in adhesion, and is convenient for taking the stuck objects off the sealing film.

The reflecting film (tin foil paper) and the sealing film (food preservative film) with the sticky area (double-sided adhesive tape) are adhered to form a whole, and the whole is used as a vibrating diaphragm for the measuring device.

(4) Light source

And a light source 6 for generating a light beam and irradiating the light beam onto the reflective film. The implementation of the light source 6 is not limited, for example, in the specific embodiment: the light source 6 is a laser pen.

In this embodiment, preferably, the light source 6 is a red laser pen, and a hand holds the laser pen to irradiate laser to the reflective film.

(5) Screen (B)

The screen 7 is used for receiving and displaying the light beam reflected by the reflecting film. The implementation of the screen 7 is not limited, for example, in a specific embodiment: the screen 7 can be a projection screen, an opaque flat plate and a wall, is arranged beside the cup body and is arranged opposite to the position of a person.

In this embodiment, preferably, the screen 7 is a wall, so that an additional device is not required, and the cost is saved. After the red laser of the laser pen irradiates the tin foil paper, the red laser can be reflected to the wall to form a light spot 8.

(6) Control terminal

The control terminal is in communication connection with the sound source 2 and is used for controlling the sound production frequency of the sound source 2. The implementation of the control terminal is not limited, but for example, in a specific embodiment: the control terminal selects a smart phone.

The communication connection between the control terminal and the sound source 2 is not limited, and for example, in a specific embodiment: the control terminal and the sound source 2 adopt wireless communication, such as WIFI and Bluetooth; or a small hole can be dug at the bottom of the cup body, and the control terminal is communicated with the sound source 2 in a wired mode.

In this embodiment, preferably, the smartphone and the audio box are connected by bluetooth communication.

Before measuring the quality of a sample to be measured, arranging a measuring device, specifically as follows:

firstly, the side of the Bluetooth sound box provided with the loudspeaker faces upwards and is horizontally placed at the bottom in the water cup.

Then, the tinfoil paper is pasted on the upper surface of the food preservative film by using double-sided adhesive, and a round double-sided adhesive is pasted beside the tinfoil paper and on the upper surface of the food preservative film.

And then the food preservative film is stuck at the opening edge of the water cup, the opening of the water cup is sealed, and the food preservative film is formed into a tight state. The position of the tin foil paper is adjusted in the pasting process, so that the tin foil paper is positioned beside the central position of the opening of the water cup, and the circular double-sided adhesive tape is positioned at the central position of the opening of the water cup. The water cup with the Bluetooth sound box and the vibrating diaphragm is placed on a platform, such as a desk.

And finally, preparing a laser pen, calling APP software Frequency Sound Generator of the smart phone and connecting the APP software Frequency Sound Generator with the Bluetooth Sound box.

As shown in fig. 2, the quality measurement of the sample to be measured is performed by the following steps:

1. adjusting the light path to make the light beam emitted by the light source form a light spot on the screen after being reflected by the reflecting film

A person holds the laser pen by hand and stands beside the desk and faces to the wall; and opening the vibrating diaphragm of the laser pen aligned with the water cup opening, and allowing the red laser to irradiate the tin foil paper. And adjusting the incident angle of the red laser to enable the red laser to form a light spot on the wall after being reflected by the tin foil paper. The light path is adjusted to relatively fix the light spot at a certain position, so that the effect of easy observation is achieved.

2. Controlling the sound source to emit sound waves with different frequencies to the diaphragm, and observing the change of light spots to measure to obtain the resonant frequency of the diaphragm

The smart phone is operated by the other hand of a person, sound waves are emitted by the Bluetooth sound box in a frequency sweeping mode through APP software, the loudness of the sound waves is set to be 50 of the default volume of the Bluetooth sound box, and the frequency sweeping is set to be 1Hz in a stepping mode. While changing the acoustic frequency, a human eye observes the light spot with the naked eye. When the acoustic wave of a certain frequency is sent to the vibrating diaphragm, through the lever amplification effect of light path, show on the wall with the less range change amplification of vibrating diaphragm, the vibrating diaphragm vibration state changes and makes reflection light spot size change, can observe that the facula shape is obviously tensile, the obvious grow of size (become the centimetre level from the millimeter level), and this frequency can directly read from APP software. The frequency of the acoustic wave is continuously changed, and the size of the light spot can be observed to gradually return to the original millimeter-scale size. The process that the light spot is obviously stretched from shape and obviously enlarged in size to gradually reduced corresponds to the change range of the frequency of the sound wave of about tens of Hz. Within the frequency range of dozens of Hz, there is a sound wave frequency which can maximize the size of the light spot, and the frequency is the resonance frequency of the diaphragm. As shown in fig. 3, when the acoustic frequency reaches around 450Hz, the spot size starts to become large; when the acoustic frequency reaches 470Hz, the spot size is the maximum, and the acoustic frequency is the diaphragm resonance frequency. For the visual contrast effect of convenience, fig. 3 shows with the two-coordinate graph, and the left side ordinate is the spot size that the vibrating diaphragm corresponds.

3. Fixing an object of known mass to the surface of a diaphragm

For convenience of description, 1 rice grain is selected for the known mass. 1 piece of rice is placed in a sticky area at the center of the diaphragm, the rice is stuck by the double-sided adhesive tape and forms a combination body with the diaphragm, and the combination body of the known quality object and the diaphragm is defined as a first combination body.

4. Controlling the sound source to emit sound waves with different frequencies to the diaphragm, and observing the change of the light spots to measure the resonant frequency of the first combination of the object with the known mass and the diaphragm

And controlling the Bluetooth sound box to emit sound waves in a frequency sweeping mode, wherein the frequency sweeping is set to be 1Hz in a stepping mode. While changing the acoustic frequency, a person observes the light spot with naked eyes, finds out the acoustic frequency when the size of the light spot is maximized and the frequency is the resonance frequency of the combination of the rice and the vibrating diaphragm and is defined as the first combination resonance frequency. As shown in fig. 3, when the frequency of the acoustic wave reaches around 250Hz, the spot size starts to become large; when the sound wave frequency reaches 310Hz, the light spot size is the maximum, and the sound wave frequency at this moment is the resonance frequency of the first combination of the diaphragm and 1 piece of rice. For the visual contrast effect, fig. 3 shows with a double-coordinate graph, and the right ordinate is the light spot size corresponding to the diaphragm and 1 rice.

5. Removing the object with known mass from the surface of the diaphragm, and fixing the sample to be measured on the surface of the diaphragm

Get 1 rice that bonds from the bonding region on vibrating diaphragm surface, can press from both sides with tweezers and get, then will await measuring the sample and glue the bonding region on vibrating diaphragm surface, await measuring the sample and form a combination with the vibrating diaphragm after being glued by the double faced adhesive tape, will await measuring the combination definition of sample and vibrating diaphragm as the second combination.

6. Controlling the sound source to emit sound waves with different frequencies to the vibrating diaphragm, and observing the change of light spots to measure the resonance frequency of the second combination of the sample to be measured and the vibrating diaphragm

And controlling the Bluetooth sound box to emit sound waves in a frequency sweeping mode, wherein the frequency sweeping is set to be 1Hz in a stepping mode. And while changing the acoustic frequency, observing the light spot by using naked eyes, and finding out the acoustic frequency when the size of the light spot is maximum, wherein the frequency is the resonance frequency of the combination of the sample to be detected and the vibrating diaphragm and is defined as the resonance frequency of a second combination.

7. Comparing the resonance frequency of the first combination with the resonance frequency of the second combination to obtain the mass of the sample to be measured

The known mass object is equivalent to a balance weight, and when the resonance frequency of the first combination is the same as that of the second combination, the mass of the sample to be measured is the same as that of the known mass object. In specific embodiments, the known mass object may be selected from a plurality of known mass objects, such as: 1 white granulated sugar, 2 rice, 1 mung bean, 1 soybean, and the like; the white granulated sugar, the rice, the mung beans and the soybeans are respectively stuck on the vibrating diaphragm in a single or combined mode, a plurality of different first combinations can be formed with the vibrating diaphragm, and the resonance frequencies of the first combinations are respectively measured. And comparing the second combination resonance frequency with the plurality of first combination resonance frequencies to obtain the mass of the sample to be measured.

The technical scheme provided by the embodiment utilizes the principle that the resonance frequency of the object has correlation with the mass of the object, and because the change of the resonance frequency has high sensitivity to the change of the mass of the object, the high measurement precision can be obtained by selecting the proper film size and thickness, such as: the mass of 1 rice is about 0.02 g, and the mass of 1 white sugar (fine white sugar) is about 0.001g, so the measurement precision of the technical scheme provided by the embodiment can reach 0.001g, which is equivalent to that of an electronic balance and exceeds that of a mechanical balance.

Compared with the electronic balance purchased, the device used in the measurement of the technical scheme provided by the embodiment can select common articles in daily life, does not have the environmental regulation cost in the use process, and has low measurement cost.

Meanwhile, the technical scheme provided by the embodiment is simple and easy to arrange, and the resonance frequency is the inherent property of the object, so that the repeatability and the stability of the measuring method are high. The measuring device has long service life, and the problems of rusting of a mechanical balance and aging of electronic components of the electronic balance do not exist.

Example 2

In the technical scheme of the embodiment 1, during the measurement process, a person needs to hold the laser pen and keep the laser pen basically still, and when the APP software is operated, eyes need to keep staring at light spots on the wall, so that fatigue is generated after a long time, and the measurement operation is inconvenient.

In order to solve the technical problems, the following technical scheme is adopted:

the measuring device also comprises a bracket 9 and an image acquisition device 10;

the bracket 9 is positioned beside the cup body, and the light source 6 and the image acquisition equipment 10 are arranged on the bracket 9;

the image acquisition device 10 performs image acquisition on the light spot 8 and transmits the acquired image to the terminal device.

The working principle of example 2 is explained in detail below:

as shown in fig. 4, a bracket 9 is arranged beside the desk on which the water cup 1 is arranged, and the realization mode of the bracket 9 is not limited and can be obtained in any way realized by the prior art. The support 9 is provided with a flat plate for placing articles, the height of the flat plate from the ground is higher than that of the cup rim from the ground, and the flat plate can be one layer or multiple layers.

The implementation of the image capturing device 10 is not limited, for example, in the specific embodiment: image acquisition equipment 10 chooses for use high accuracy CCD camera, and the camera is from taking 4G or WIFI function. In this embodiment, the image capturing device 10 selects 4K hua as a haisi chip mini wireless high-precision CCD camera.

The implementation manner of the terminal device is not limited, and for example, in a specific embodiment: the smart phone is selected, APP software of the smart phone can be connected with the camera, and images shot by the camera are displayed on the smart phone.

Put laser pen, camera on the flat board of support, be connected the camera with the smart mobile phone, use APP software to call out the image that the camera was shot. The direction of the light beam emitted by the laser pen and the shooting angle of the camera are well adjusted, so that light spots on the wall can be clearly displayed on the smart phone. Then the position of the laser pen and the camera is fixed, for example, a book cushion is used under the laser pen and the camera.

When the measurement method in embodiment 1 is used, by adopting the technical scheme of this embodiment, a person can simultaneously control the bluetooth speaker on the smart phone and observe the change condition of the light spot, which is more convenient for operation.

Example 3

For the technical solutions of embodiment 1 and embodiment 2, when observing the spot change, a person needs to find the maximum size in the spot change process. However, since the spot reaches the maximum size and becomes smaller from the maximum size during the variation process, an error may occur in the observation by the naked eye, so that the obtained resonance frequency deviates from the true resonance frequency, for example, deviates from 1-2Hz, thereby affecting the accuracy of the quality measurement.

and coordinates are set on the screen, and the change of the light spot is observed by combining the coordinates, so that the maximum size in the change process of the light spot is obtained.

The working principle of example 3 is explained in detail below:

the implementation of setting the coordinates on the screen is not limited, and for example, in a specific embodiment: a piece of checkerboard paper of a4 may be attached to the wall as shown in fig. 5. When a person observes the change of the light spot, the ordinate and the abscissa on the grid coordinate paper are used as references, so that the visual deviation of the size can be avoided by observing with naked eyes, and fig. 5(a) is an observation effect graph of the light spot size when the sound frequency emitted by the sound source is not the resonance frequency. Fig. 5(b) is an observation effect diagram in which the spot size is increased when the frequency of the sound emitted from the sound source is the resonance frequency. Meanwhile, when the sound wave frequency emitted by the Bluetooth sound box is controlled, the frequency sweeping is carried out step by step according to the frequency sweeping frequency of 0.1-Hz, so that more accurate resonance frequency can be obtained, and the precision of quality measurement is further improved.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims

1. A mass measurement method based on acoustic wave resonance is characterized by comprising the following steps:

fixing an object with known mass on the surface of the diaphragm;

controlling a sound source to emit sound waves with different frequencies to the vibrating diaphragm, and measuring the resonant frequency of the first combined body of the object with the known mass and the vibrating diaphragm by observing the change of the light spots;

2. The acoustic resonance-based mass measurement method of claim 1, wherein: before measurement, the measurement device is arranged, specifically as follows:

placing a sound source in the cup body;

sealing the opening of the cup body by using a sealing film;

and connecting the sound source through the control terminal.

3. The acoustic resonance-based mass measurement method of claim 1, wherein: the measuring device also comprises a bracket and image acquisition equipment;

the image acquisition equipment acquires images of the light spots and transmits the acquired images to the terminal equipment.

4. The acoustic resonance-based mass measurement method of claim 3, wherein: the image acquisition equipment is a camera, and the terminal equipment is a smart phone.

5. The acoustic resonance-based mass measurement method of claim 1, wherein: and setting coordinates on the screen, and observing the change of the light spot by combining the coordinates to obtain the maximum size in the change process of the light spot.

6. The acoustic resonance-based mass measurement method of claim 5, wherein: coordinates are set on the screen using checkerboard paper.

7. The acoustic resonance-based mass measurement method of claim 6, wherein: when the sound source is controlled to send out sound waves with different frequencies to the diaphragm, the sweep frequency is stepped to be 1Hz or 0.1 Hz.