Ultrasonic non-contact liquid volume measurement device and method

Abstract

The present invention relates to an ultrasonic non-contact liquid volume measurement device, comprising an ultrasonic measurement sensor, a thermocouple thermometer, a central processing unit, a robotic arm assembly, a liquid carrying container, a container positioning plate, a display control module, and a power supply. The device is characterized in that: a transmitting end and a receiving end of the ultrasonic measurement sensor are integrated into the same component; the ultrasonic measurement sensor is configured to measure the liquid level; and the thermocouple thermometer is configured to correct the liquid level measured by the ultrasonic measurement sensor; the robotic arm assembly is used to drive the ultrasonic measurement sensor and the thermocouple thermometer to determine cross-sectional information of the liquid carrying container; the central processing unit has a built-in controller that processes and calculates data transmitted back by the ultrasonic measurement sensor, the thermocouple thermometer, and the stepping motor of the robotic arm assembly to obtain liquid volume data; the solution of the present invention has a simple structure and accurate calculated data.

Description

Technical Field

[0001] The present invention relates to the field of laboratory devices, in particular to a measuring device and method for testing the volume of liquid in a non-contact manner during evaporation, and specifically discloses an ultrasonic non-contact liquid volume measuring device and method. Background Art

[0002] In the field of water treatment, especially in the fields of conventional environment and radiation environment monitoring, during the evaporation and concentration process of liquid samples, it is necessary to know the volume of the liquid sample being processed, and on the other hand, to monitor the volume of the liquid during the treatment process in order to control the final liquid volume after treatment to be within the required range.

[0003] During the testing process of liquid samples, it is usually necessary to add an appropriate amount of acid solution such as nitric acid or hydrochloric acid for acidification to ensure the uniformity of the liquid sample and reduce its adsorption to the evaporation container. If the volume measuring probe or the measuring container directly contacts the sample, the probe must be highly resistant to acid corrosion, and cross-contamination is easily generated when handling samples with different contamination levels. Therefore, it is necessary to develop a non-contact liquid volume measurement device. In addition to contact with the evaporation container (such as a beaker or evaporating dish), the liquid sample no longer comes into direct contact with any other components. Due to the evaporation of the liquid sample, acidic water vapor, referred to as acid mist, is generated. How to account for the impact of acid mist on the measurement device and acid corrosion also needs to be considered during development.

[0004] In the publicly available prior art, non-contact volume measurement is achieved through optical or capacitive measurement devices or methods. Optical measurement is complex in structure, and its optical path is easily obstructed by liquid vapor, affecting measurement, making it difficult to apply to liquid samples that have been evaporated. Capacitive measurement determines the volume by measuring the capacitance of a liquid sample. This requires the liquid sample to be placed in a container equipped with a capacitor for measurement, making it difficult to heat and evaporate the liquid sample. Furthermore, the structure is relatively complex, as exemplified by the technical approach employed in Chinese Patent CN113237526A.

[0005] For example, the prior art FR2565345A1 and EP263036A2 both disclose volume measurement methods based on ultrasound. However, the above measurement methods do not consider the factors affecting the accuracy of the volume measurement value caused by the evaporation process.

[0006] Based on the above problems, the inventor proposes the following solutions. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies of the existing technology and to provide an ultrasonic non-contact liquid volume measuring device.

[0008] A non-contact liquid volume measurement device based on ultrasound comprises an ultrasonic measurement sensor, a thermocouple thermometer, a central processing unit, a robotic arm assembly, a liquid carrying container, a container positioning plate, a display control module, and a power supply. The device is characterized in that: a transmitting end and a receiving end of the ultrasonic measurement sensor are integrated into the same component; the ultrasonic measurement sensor is fixedly mounted on the robotic arm and located directly above the liquid surface of the liquid sample; the ultrasonic measurement sensor can move with the robotic arm, and transmits ultrasonic waves outward through the transmitting end. The ultrasonic waves are reflected back to the receiving end after being blocked by the liquid surface or the liquid carrying container; the ultrasonic measurement sensor is equipped with a data signal line connected to the central processing unit; and the ultrasonic measurement sensor is equipped with a power supply line connected to the DC power supply.

[0009] Furthermore, a thermocouple thermometer is fixedly mounted on the robotic arm in parallel with the ultrasonic measurement sensor, a thermocouple probe of the thermocouple thermometer is arranged in parallel with and adjacent to the ultrasonic measurement sensor, the thermocouple thermometer is used to measure the air temperature around the ultrasonic measurement sensor, the thermocouple thermometer is configured with a data signal line, the data signal line is connected to the central processing unit, and the thermocouple thermometer is configured with a power supply line, the power supply line is connected to a DC power supply;

[0010] Furthermore, the central processing unit has a built-in controller and a processing calculation program to process and calculate the data sent back by the ultrasonic measurement sensor, the thermocouple thermometer and the stepper motor of the robotic arm assembly to obtain liquid volume data, and at the same time can send control signals to the ultrasonic measurement sensor and the stepper motor of the robotic arm assembly;

[0011] Furthermore, the robotic arm assembly includes a DC motor, a sliding shaft, a robotic arm, etc., and is installed above the liquid holding container. The installation distance of the robotic arm is preferably to ensure that the liquid level is outside the measurement blind zone of the ultrasonic measurement sensor. The central processing unit sends a control signal to the stepper motor to control the speed and number of revolutions of the stepper motor, thereby accurately controlling the movement speed of the robotic arm.

[0012] Furthermore, the liquid carrying container is placed on the container positioning plate, directly below the ultrasonic measurement sensor. Preferably, the cross-section of the container is circular, rectangular or square, and there are no special requirements for the material. For the liquid sample to evaporate during heating, it can be optionally a cylindrical beaker. If it is in a non-heating state, it can be optionally a plastic cylindrical box, etc.

[0013] Furthermore, a container positioning plate is positioned below the liquid holding container. The surface of the container positioning plate is marked with a scale. The smallest scale graduation on the scale is 1-5 mm, preferably 1-2 mm, and more preferably 1 mm. The midpoint of the scale is configured to be directly below the ultrasonic measurement sensor in the vertical direction. The container positioning plate is used to position the liquid holding container directly below the ultrasonic measurement sensor in the vertical direction to ensure accurate measurement. Preferably, the scale is a cross scale, or is specifically configured according to the liquid holding container. For example, when the container is a regular polygon, the scale type is adaptively configured according to the angle of the polygon.

[0014] Furthermore, it also includes a display control module connected to the central processing unit for setting measurement parameters and viewing measurement results.

[0015] Furthermore, the ultrasonic measurement sensor, thermocouple thermometer, central processing unit, robotic arm assembly, display control module, and power supply are all electrically connected.

[0016] Another aspect of the present invention is to provide a method for measuring the volume of a liquid using an ultrasonic non-contact liquid volume measuring device, the method comprising the following steps:

[0017] Step a: Positioning the liquid holding container at the center of the positioning plate;

[0018] Step b: Input the robot arm movement speed v and the ultrasonic measurement sensor measurement interval time T;

[0019] Step c: Correcting the ultrasonic wave propagation velocity to obtain the cross-sectional information of the liquid carrying container;

[0020] Step d: Get the liquid level h y1 , obtain the liquid sample volume;

[0021] Step e: obtaining the real-time volume of the heated and evaporated liquid sample;

[0022] Preferably, step a. placing a liquid holding container containing liquid on a container positioning plate, and adjusting the container based on the values of the container on the four axes of the cross scale so that the liquid holding container is placed in the center of the container positioning plate, thereby ensuring that the ultrasonic measurement sensor moves radially along the diameter of the projected circle of the liquid holding container;

[0023] Preferably, step b. setting the robot arm movement speed v and the ultrasonic measurement sensor measurement interval T in the display control module, setting the ultrasonic measurement sensor and the thermocouple thermometer to move inward from the periphery of the container positioning plate with the robot arm into the projection of the liquid carrying container, and performing measurements according to the set parameters, preferably the robot arm moves within the same horizontal plane;

[0024] Preferably, in step c. correcting the ultrasonic velocity, the thermocouple thermometer measures the air temperature around the ultrasonic measurement sensor in real time and feeds it back to the central processing unit, which corrects the ultrasonic propagation velocity. Combined with the acquired ultrasonic flight time t, the distance h = St / 2 from the reflection point to the ultrasonic measurement sensor is calculated. The distance H from the ultrasonic measurement sensor to the container positioning plate has been measured when there is no liquid-carrying container. With (Hh) as the vertical coordinate and the robot arm movement displacement v as the horizontal coordinate, the central processor can obtain a series of measurement point data.

[0025] For accurate measurement, the robot arm's movement speed in this step is preferably controlled below 5 mm / s, preferably 1-5 mm / s, more preferably 2-4 mm / s, and most preferably 2 mm / s. A linear fit is used to obtain the cross-sectional information of the liquid carrier container. The distance from the bottom inner wall of the liquid carrier container to the container positioning plate can also be obtained, defined as h0.

[0026] Preferably, in step d, the liquid sample is injected into the liquid holding container. Before the heating and evaporation process, the thermocouple thermometer and the ultrasonic measurement sensor measure the liquid surface to obtain the distance data h1, and the central processing unit calculates the liquid surface height h. y1 =H-h1-h0.

[0027] The CPU selects four adjacent measuring points P1, P2, P3, and P4 where the (Hh) value suddenly changes according to the cross section measured in step c, as shown in the attached figure. Figure 3 As shown, the time difference t between P1 and P2 is 1-2 , time difference between P3 and P4 t 3-4 , and the product of the fixed moving speed of the robot arm, the diameter of the liquid carrying container is calculated to be R1 = vt 1-2 and R2 = vt 3-4 The average of the two values is the diameter R of the liquid container. The CPU calculates the volume of the liquid sample as V = π(R / 2). 2 h y1 Preferably, during the heating and evaporation process of the liquid sample, the thermocouple thermometer and the ultrasonic measurement sensor are used to regularly inspect the liquid level along with the robotic arm, and the central processing unit obtains a set of data (Hh-h0) n , as attached Figure 4 .

[0028] Especially during the evaporation of the solution, the presence of steam above the liquid surface will affect the propagation speed of the ultrasonic wave. At this time, it is not possible to make accurate corrections based on the temperature. Figure 4 As shown, there will be some individual data deviations, in which case the data needs to be removed.

[0029] Preferably, the method for removing the deviated data comprises the following steps:

[0030] First, calculate the m-point data set (Hh-h0) in sequence n ~(Hh-h0) n+m (According to (Hh-h0)1~(Hh-h0)5, (Hh-h0)2~(Hh-h0)6, (Hh-h0)3~(Hh-h0)7… and so on) average value (Hh-h0) avgm and standard deviation σ n , divide the two and get the relative deviation RSD n , when there is an abnormal data, m abnormal RSDs will appear continuously n , set RSD n The threshold value is set to 1-5%, preferably 2-4%, more preferably 2-3%, more preferably 2%. When the relative deviation RSD is obtained according to the calculation n Above the threshold, the last RSD appears n Abnormal (Hh-h0) n After all the data of the measurement are processed and qualified according to this method, the average value of the remaining data (Hh-h0) is taken. avg , the volume of the liquid sample is V p =π(R / 2) 2 (Hh-h0) avg According to this algorithm, the real-time volume of the heated and evaporated liquid sample can be obtained.

[0031] Preferably, the value of m can be selected to be 5-10, preferably 5-7, preferably 5-6.

[0032] Preferably, if there is no obvious vapor between the solution surface and the ultrasonic measurement sensor, follow the above steps a to e without performing the above steps (Hh-h0). n Accurate data can also be obtained by eliminating data. The volume of the liquid sample is V p The calculation is simpler.

[0033] Preferably, if the diameter of the liquid carrying container is certain, the process of calculating the container diameter in step d above can be omitted, and the diameter can be directly input into the display control module for normal operation.

[0034] Preferably, the liquid carrying container is a cylindrical or rectangular container, preferably a beaker.

[0035] The present application also seeks to protect an application of an ultrasonic non-contact liquid volume measuring device, specifically for measuring the volume of a liquid whose liquid level changes during the evaporation process of the liquid.

[0036] Beneficial effects of the present invention:

[0037] 1. The device has a simple structure. The liquid sample does not come into contact with any other components except the carrying container. It has a wide range of applications and does not have high requirements for liquid samples. It can be acidic, alkaline and other corrosive liquids. It also avoids the problem of cross contamination.

[0038] 2. The precise data elimination method enables the device to be applied to the real-time measurement of the volume of heated and evaporated liquid samples, thereby controlling the final volume.

[0039] 3. The precise container diameter method can simply measure the internal diameter of the beaker and accurately obtain the data, which makes up for the defect that other measurement methods are difficult to accurately measure the internal diameter of containers similar to beakers.

[0040] 4. Easy to operate. As long as the liquid-carrying container is a regular cylinder or rectangle, the device can accurately measure the parameters required for volume calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 Schematic diagram of the ultrasonic non-contact liquid volume measuring device of the present invention;

[0043] Figure 2 This is a schematic diagram of the position of the liquid carrying container and the ultrasonic measurement sensor located at the center of the positioning plate according to the present invention;

[0044] Figure 3 This is the data point fitting diagram of the ultrasonic measurement device with an interval time of 1s;

[0045] Figure 4 Schematic diagram of inspection data for thermocouple thermometers and ultrasonic measurement sensors

[0046] In the figure: 1. Ultrasonic measurement sensor; 2. Thermocouple thermometer; 3. Central processing unit; 4. Robotic arm assembly; 5. Liquid carrying container; 6. Container positioning plate; 7. Display control module. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0048] In this application, terms indicating positional relationships and connection relationships indicate positions or positional relationships based on those shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific position, or to being constructed or operated in a specific position.

[0049] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Figures 1 to 4 , and describes the application in detail with reference to embodiments.

[0050] Example 1

[0051] A non-contact liquid volume measurement device based on ultrasound comprises an ultrasonic measurement sensor 1, a thermocouple thermometer 2, a central processing unit 3, a robotic arm assembly 4, a liquid carrying container 5, a container positioning plate 6, a display control module 7, and a power supply. The device is characterized in that a transmitting end and a receiving end of the ultrasonic measurement sensor 1 are integrated into the same component, the ultrasonic measurement sensor 1 is fixedly mounted on the robotic arm 4 and is located directly above the liquid surface of the liquid sample. The ultrasonic measurement sensor 1 can move with the robotic arm 4, and transmits ultrasonic waves outward through the transmitting end. The ultrasonic waves are blocked by the liquid surface or the liquid carrying container and then reflected back to the receiving end. The ultrasonic measurement sensor 1 is also equipped with a data signal line connected to the central processing unit. The ultrasonic measurement sensor is also equipped with a power supply line connected to the DC power supply.

[0052] A thermocouple thermometer 2 is fixedly mounted on the robotic arm 4 in parallel with the ultrasonic measurement sensor 1. The thermocouple probe of the thermocouple thermometer 2 is arranged in parallel with and adjacent to the ultrasonic measurement sensor 1. The thermocouple thermometer 2 is used to measure the air temperature around the ultrasonic measurement sensor 1. The thermocouple thermometer 2 is configured with a data signal line, which is connected to the central processing unit 3. The thermocouple thermometer 2 is configured with a power supply line, which is connected to a DC power supply.

[0053] The central processing unit 3 has a built-in controller and a processing and calculation program, which processes and calculates the data sent back by the ultrasonic measurement sensor 1, the thermocouple thermometer 2 and the stepper motor of the robotic arm assembly 4 to obtain liquid volume data, and can also send control signals to the ultrasonic measurement sensor 1 and the stepper motor of the robotic arm 4 assembly;

[0054] The robotic arm assembly 4 includes a stepper motor, a sliding shaft, a robotic arm, etc., and is installed above the liquid carrying container 5. The installation distance of the robotic arm is preferably to ensure that the liquid level is outside the measurement blind zone of the ultrasonic measurement sensor 1. The central processing unit 3 sends a control signal to the stepper motor to control the speed and number of revolutions of the stepper motor, thereby accurately controlling the movement speed of the robotic arm.

[0055] The liquid carrying container 5 is placed on the container positioning plate 6 and directly below the ultrasonic measurement sensor 1 . The cross section of the container is circular and is a cylindrical beaker.

[0056] The container positioning plate 6 is located below the liquid holding container 5. A scale is marked on the surface of the container positioning plate 6. The smallest graduation on the scale is 1 mm. The midpoint of the scale is configured to be directly below the ultrasonic measurement sensor 1 in the vertical direction. The container positioning plate 6 is used to place the liquid holding container 5 directly below the ultrasonic measurement sensor 1 in the vertical direction to ensure accurate measurement. The scale is a cross-shaped scale.

[0057] It also includes a display control module 7 connected to the central processor 3 for setting measurement parameters and viewing measurement results.

[0058] The ultrasonic measurement sensor 1 , the thermocouple thermometer 2 , the central processing unit 3 , the robotic arm assembly 4 , the display control module 7 , and the power supply are all electrically connected.

[0059] Another aspect of the present invention is to provide a method for measuring the volume of a liquid using an ultrasonic non-contact liquid volume measuring device, the method comprising the following steps:

[0060] Step a. Place the liquid-containing container on the container positioning plate. Adjust the container based on the values of the container on the four axes of the cross scale so that the liquid-containing container is placed in the center of the container positioning plate. This ensures that the ultrasonic measurement sensor moves radially along the diameter of the projected circle of the liquid-containing container.

[0061] Step b. Setting the robot arm movement speed v and the ultrasonic measurement sensor measurement interval T in the display control module, setting the ultrasonic measurement sensor and the thermocouple thermometer as the robot arm moves inward from the periphery of the container positioning plate into the projection of the liquid carrying container, and performing measurements according to the set parameters. Preferably, the robot arm moves within the same horizontal plane;

[0062] Step c. Correct the ultrasonic velocity. The thermocouple thermometer measures the air temperature around the ultrasonic sensor in real time and feeds it back to the central processor, which corrects the ultrasonic propagation velocity. Combined with the acquired ultrasonic flight time t, the distance h = St / 2 from the reflection point to the ultrasonic measurement sensor is calculated. The distance H from the ultrasonic measurement sensor to the container positioning plate has been measured without a liquid-carrying container. With (Hh) as the vertical coordinate and the robot arm displacement v as the horizontal coordinate, the central processor can obtain a series of measurement point data.

[0063] In this step, the movement speed of the robot arm is controlled below 2 mm / s.

[0064] Step d. Inject the liquid sample into the liquid holding container. Before heating and evaporation, the thermocouple thermometer and ultrasonic measurement sensor measure the liquid surface to obtain the distance data h1. The central processor calculates the liquid surface height h. y1 =H-h1-h0.

[0065] The CPU selects four adjacent measuring points P1, P2, P3, and P4 where the (Hh) value suddenly changes according to the cross section measured in step c, as shown in the attached figure. Figure 3 As shown, the time difference t between P1 and P2 is 1-2 , time difference between P3 and P4 t 3-4 , and the product of the fixed moving speed of the robot arm, the diameter of the liquid carrying container is calculated to be R1 = vt 1-2 and R2 = vt 3-4 The average of the two values is the diameter R of the liquid container. The CPU calculates the volume of the liquid sample as V = π(R / 2). 2 h y1 .

[0066] e. During the heating and evaporation process of the liquid sample, the thermocouple thermometer and ultrasonic measurement sensor are used with the robotic arm to regularly inspect the liquid level, and the central processing unit obtains a set of data (Hh-h0) n , as attached Figure 4 .

[0067] Especially during the evaporation of the solution, the presence of steam above the liquid surface will affect the propagation speed of the ultrasonic wave. At this time, it is not possible to make an accurate correction based on the temperature influence factor. Figure 4 As shown, there will be some individual data deviations, in which case the data needs to be removed.

[0068] The method for eliminating the deviated data comprises the following steps:

[0069] First, calculate the 5-point data set (Hh-h0) in sequencen ~(Hh-h0) n+5 (According to (Hh-h0)1~(Hh-h0)5, (Hh-h0)2~(Hh-h0)6, (Hh-h0)3~(Hh-h0)7… and so on) average value (Hh-h0) avg5 and standard deviation σ n , divide the two and get the relative deviation RSD n , when there is an abnormal data, there will be 5 abnormal RSDs in succession n , set RSD n The threshold is set to 2%. When the relative deviation RSD is calculated n Above the threshold, the last RSD appears n Abnormal (Hh-h0) n After all the data of the measurement are processed and qualified according to this method, the average value of the remaining data (Hh-h0) is taken. avg , the volume of the liquid sample is V p =π(R / 2) 2 (Hh-h0) avg According to this algorithm, the real-time volume of the heated and evaporated liquid sample can be obtained.

[0070] The liquid carrying container is a cylindrical beaker.

[0071] Table 1 Example of data elimination (Hh-h0) in this embodiment

[0072]

[0073]

[0074] Example 2

[0075] Example 2 is basically the same as Example 1, except that if there is no obvious vapor between the solution surface and the ultrasonic measurement sensor, the above steps a to e are followed without performing the above steps (Hh-h0). n Accurate data can also be obtained by eliminating data. The volume of the liquid sample is V p The calculation is simpler.

[0076] Sample V p =V=π(R / 2) 2 h y1 .

[0077] Example 3

[0078] Example 3 is basically the same as Example 1, except that the diameter of the liquid carrying container is fixed, and the process of calculating the container diameter in step d is omitted. The normal operation can be achieved by directly inputting the diameter in the display control module.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for measuring liquid volume based on an ultrasonic non-contact liquid volume measuring device, characterized in that: The ultrasonic non-contact liquid volume measuring device includes an ultrasonic measuring sensor, a thermocouple thermometer, a central processing unit, a robotic arm assembly, a liquid carrying container, a container positioning plate, a display control module, and a power supply. The transmitting end and the receiving end of the ultrasonic measuring sensor are integrated on the same component. The ultrasonic measuring sensor is configured to measure the liquid level, and the thermocouple thermometer is configured to calibrate the ultrasonic propagation speed. The robotic arm assembly is used to drive an ultrasonic measurement sensor and a thermocouple thermometer to determine cross-sectional information of the liquid-carrying container; The central processing unit has a built-in controller that processes and calculates the data sent back by the ultrasonic measurement sensor, the thermocouple thermometer, and the stepper motor of the robotic arm assembly to obtain liquid volume data; The liquid volume measurement method includes the following steps: Step a: Positioning the liquid container at the center of the positioning plate. Place the liquid container on the container positioning plate and adjust the container based on the values of the container on the four axes of the cross scale so that the liquid container is placed in the center of the container positioning plate. Step b: setting the robot arm movement speed v and the ultrasonic measurement sensor measurement interval T in the display control module, and setting the ultrasonic measurement sensor and the thermocouple thermometer to move inward from the periphery of the container positioning plate with the robot arm and enter the projection of the liquid holding container; Step c: The air temperature around the ultrasonic sensor is measured in real time using a thermocouple thermometer and fed back to the central processor. The central processor calculates the ultrasonic propagation speed using the following formula: S= m / s; Correction is performed, and combined with the acquired ultrasonic flight time t, the distance h = St / 2 from the reflection point to the ultrasonic measurement sensor is calculated. The distance H from the ultrasonic measurement sensor to the container positioning plate is defined, with (Hh) as the vertical coordinate and the robot arm movement displacement v as the horizontal coordinate. The measurement point data is obtained by plotting the points, and a linear fit is used to obtain the cross-sectional data of the liquid holding container. At the same time, the distance from the bottom inner wall of the liquid holding container to the container positioning plate can be obtained, which is defined as h0. The movement speed of the robot arm is controlled at 2-4 mm / s. Step d: Pour the liquid sample into the liquid holding container and define the liquid level as h y1 Before the heating and evaporation process, the thermocouple thermometer and ultrasonic measurement sensor are used to measure the liquid surface to obtain the distance data h1. According to the following formula: h y1 =H-h1-h0 to get the liquid level h y1 , obtain the volume of the liquid sample before evaporation; Step e: obtaining the real-time volume of the heated and evaporated liquid sample based on the corrected ultrasonic propagation velocity, the cross-sectional information of the carrier container, and the liquid level; Based on the cross-sectional data of the liquid container measured in step c, select four adjacent measurement points P1, P2, P3, and P4 where the (Hh) value changes suddenly. Calculate the diameters R1 and R2 of the liquid container by the horizontal displacement between P1 and P2, and between P3 and P4, respectively. Take the average of these two values to obtain the diameter R of the liquid container according to the following formula: V=π(R / 2) 2 h y1 Get the volume of the liquid sample; Step e. During the heating and evaporation process of the liquid sample, the thermocouple thermometer and ultrasonic measurement sensor are regularly inspected with the robotic arm to inspect the liquid level, and the central processor obtains a set of data (Hh-h0) n, which is set to eliminate deviation data; The method for eliminating the deviated data comprises the following steps: S1: Calculate the average value (Hh-h0) of the m-point data set (Hh-h0)n~(Hh-h0)n+m in sequence avgm and standard deviation σ n , divide the two and get the relative deviation RSD n , the order of sequentially calculating the m-point data group is: (Hh-h0)1~(Hh-h0)5, (Hh-h0)2~(Hh-h0)6, (Hh-h0)3~(Hh-h0)7... and so on; S2: Set RSD n Threshold abnormal data, set RSD n The threshold is set to 1-5%. When there is an abnormal data, m abnormal RSDs are determined. n , when the relative deviation RSD is calculated n When it is higher than the threshold, the last RSD is removed n Abnormal (Hh-h0) n ; The value of m is 5-6.

2. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 1, characterized in that: The robotic arm assembly includes a DC motor, a sliding shaft, and a robotic arm. The robotic arm is controlled by a central processing unit to move from the periphery of the liquid carrying container projection or the container positioning plate to the inside.

3. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 2, characterized in that: The robotic arm moves at a speed of 1-5 mm / s.

4. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 2, characterized in that: The robotic arm moves at a constant speed of 2 mm / s.

5. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 1, characterized in that: The liquid carrying container is placed on the container positioning plate and directly below the ultrasonic measurement sensor. The cross section of the liquid carrying container is circular, rectangular or square.

6. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 1, characterized in that: The container positioning plate is located below the liquid holding container. The surface of the container positioning plate is marked with a scale having a minimum scale of 0.1-5 mm. The geometric center of the scale is configured to be directly below the ultrasonic measurement sensor in the vertical direction. The container positioning plate is used to configure the liquid holding container to be directly below the ultrasonic measurement sensor in the vertical direction. The scale is a cross-shaped scale.

7. The liquid volume measurement method based on an ultrasonic non-contact liquid volume measurement device according to claim 1, wherein the container positioning plate is located below the liquid holding container, the plate surface of the container positioning plate is marked with a scale, the minimum scale graduation of the scale is 1-2 mm, the geometric center of the scale is configured to be directly below the ultrasonic measurement sensor in the vertical direction, the container positioning plate is used to position the liquid holding container directly below the ultrasonic measurement sensor in the vertical direction, and the scale is a cross scale.

8. The liquid volume measurement method based on the ultrasonic non-contact liquid volume measurement device according to claim 1, characterized in that: When all the measured data are processed and qualified, take the average value of the remaining data (Hh-h0) avg , the volume of the liquid sample is Vp=π(R / 2) 2 (Hh-h0) avg .

9. The ultrasonic non-contact liquid volume measurement method according to claim 1, characterized in that: If there is no obvious vapor between the solution surface and the ultrasonic measurement sensor, follow steps a to e above and do not need to perform the above (Hh) n Data elimination; If the diameter of the liquid carrying container is known, the process of calculating the container diameter in step d above can be omitted, and the diameter can be directly input into the display control module to calculate the liquid volume.

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