An automatic detection device and method for a suspension

Abstract

The application discloses a kind of suspension automatic detection device and method, based on spectrophotometry and laser particle size measurement method, newly established the mathematical relationship model between the visible light transmission absorbance of suspension and wavelength, suspended particle and medium property parameter, using peristaltic pump, LED light source, multichannel visible light sensor, single-chip microcomputer, operating terminal system etc., through working circuit design and control program programming, the integrated suspension automatic detection device of sample introduction, measurement, calculation, plotting is developed, and detection operation method is established, realize the instantaneous measurement and dynamic measurement to the particle size, particle number and suspended matter mass, turbidity of statistical significance, high sensitivity, detection limit is only 1mg / L, error is less than 20%.Compared with traditional detection method, the device is small and light, simple operation, interface is clear and intuitive, non-professional personnel can use anytime and anywhere, can meet scattered sample detection, can also carry out real-time, on-line detection.

Description

Technical Field

[0001] This invention relates to the field of analytical testing technology, and in particular to an automatic detection device and method for suspensions. Background Technology

[0002] The determination of the physical properties of particulate matter in heterogeneous systems has important applications in various industries. For example, in materials synthesis, it helps monitor crystal growth information in real time; in pollution control, it helps analyze the working status of catalysts and adsorbents in water treatment; in cell or microbial culture, it helps researchers to grasp cell growth patterns in a timely manner; and in food and environmental testing, it enables timely evaluation of beverage safety and environmental quality, etc. As a heterogeneous system, suspensions differ from solutions in that the particle size, shape, and quantity of particulate matter directly affect the optical properties of the liquid.

[0003] Depending on the measurement principle, the main methods for measuring particulate matter include: sieving, microscopy, sedimentation, inductive method (Coulter method), ultrasonic method, light scattering method, and gravimetric method. Sieving is only suitable for measuring dry powders that are not easily agglomerated. Microscopy uses optical imaging to analyze factors such as particle size, shape, and structure, but it cannot measure the content and number of suspended solids. Sedimentation is based on the Stokes sedimentation formula and determines the particle size according to the final settling velocity of particles in a liquid, and can measure particle size distribution. Liu Sen et al. used gravity sedimentation with rheological coefficient correction to determine the particle size distribution of water-in-oil emulsion (Liu Sen, Yang Qiang, Lu Hao et al., Determination of particle size distribution of water-diesel emulsion by gravity sedimentation. China Testing, 2016, 42(06):50-53.). For example, the BT-1500 centrifugal sedimentation particle size analyzer developed by Dandong Baite Company can determine the particle size distribution using various sedimentation methods such as gravity sedimentation, centrifugal sedimentation, and a combination of both. However, it takes a long time to complete a single measurement. The inductive method (Coulter method) uses the change in resistance as particles suspended in an electrolyte flow through an orifice as a measure of particle size, enabling simultaneous determination of particle size and number. For example, the RC-2100 particle counter / size analyzer produced by Omec and the Winner602 automatic liquid particle counter produced by Jinan Micro-Nano can both determine the size and number of liquid particles. The ultrasonic method utilizes the relationship between the sound attenuation coefficient and particle size to determine particle size. Wu Jian et al. proposed a method for simultaneously measuring the particle size, density, and concentration of nanoparticle suspensions based on ultrasonic detection (Wu Jian, Su Mingxu, Cai Xiaoshu, Research on the Method for Simultaneous Measurement of Particle Size, Density, and Concentration of Nanoparticle Suspensions. Journal of Analytical Testing, 2011, 30(11):1246-1251), which can realize real-time monitoring of the particle phase during the processing and preparation of nanoparticles. Hou Huaishu et al. used medium- and low-frequency ultrasound to determine the average particle size and particle size distribution of particles by measuring the acoustic attenuation spectrum of ultrasound propagation in the two-phase medium of nano-TiO2 particles (Hou Huaishu, Zhang Suohuai, Nanoparticle Size Measurement Based on Medium- and Low-Frequency Ultrasound. Mechanical Engineering Materials, 2011, 35(05):80-82). Light scattering is the most widely used particle measurement method. Based on the principle of light scattering, this method can obtain the particle size distribution and concentration by measuring the scattering parameters and their combinations that are closely related to the particle size. Particle measurement methods based on light scattering can be classified into angular scattering single-particle detection method, dynamic light scattering method, diffraction scattering method, and total scattering method, depending on the different scattered signals received.The use of light scattering for the analysis of the physicochemical properties of particles has advantages such as wide applicability, wide measurement range, high accuracy, fast testing speed, and real-time online measurement (Ye Chao, Meng Rui, Ge Baozhen, A review of particle measurement methods based on light scattering. Laser & Infrared, 2015, 45(04):343-348). Currently, there are many types of laser particle size analyzers that have been developed. For example, the laser particle size analyzer (Mastersizer series) and potential and nanoparticle size analyzer (Zetasizer series) produced by Malvern Corporation in the UK, the laser particle size analyzer produced by Macchic Corporation, and the JC-SS-1Z suspended matter analyzer developed by Juchuang Environmental Protection Co., Ltd. can all accurately measure particle size and suspended matter concentration. However, the instruments are bulky, require indoor operation by professional personnel, and are expensive. The gravimetric method (GB11901-89, Determination of Suspended Solids in Water—Gravimetric Method) is the most commonly used method for determining the content of suspended solids. After filtration, the suspension remains on filter paper / membrane, which is then dried at 103–105℃ until its mass is constant, and the suspended solids content can be obtained by weighing. Although the gravimetric method is simple to operate, it is time-consuming and energy-intensive, and cannot achieve rapid online measurement.

[0004] With the development of science and technology, particulate matter measurement methods have been continuously improved, and new particulate matter measurement methods are constantly emerging. Currently, small suspended solids analyzers based on transmitted light measurement are also emerging. For example, the KN-SS10 suspended solids analyzer developed by Keno Instruments and the 6B-50SS suspended solids analyzer developed by Sheng Aohua can quickly determine the content of suspended solids in water, but they cannot simultaneously measure the size and quantity of particulate matter. Summary of the Invention

[0005] This invention establishes mathematical relationships between transmitted light and the refractive index, particle size, and number of dispersed particles, as well as the refractive index and density of the dispersion medium, based on transmitted light measurement data. It develops new methods for measuring suspended solids content, particle size, particle number, and turbidity, enabling simultaneous automatic detection of multiple parameters in suspensions offline / online, rapidly, and in real time. The instrument is small and lightweight, and very easy to operate. It can be used freely indoors, in the field, and outdoors, allowing ordinary people to operate it anytime, anywhere.

[0006] An automatic detection method for suspensions includes the following steps: S1, inputting the property parameters of the sample to be tested, including the refractive index r0 of the medium, density ρ (g / L), particle refractive index r, dilution factor β, and measurement wavelength λ (nm); S2, turning on the LED light source, and the sensor collecting the transmitted light information of the sample to be tested in the sample cell, converting it into transmitted light intensity I at different wavelengths; S3, calculating the average particle size φ (μm), number of suspended particles N (p / L), suspended matter content c (mg / L), and turbidity T (NTU) of the suspended matter in the sample to be tested based on the transmitted light intensity I at different wavelengths.

[0007] Preferably, the transmitted light intensity I0 of distilled water is obtained; the absorbance A of the sample at different wavelengths is obtained using the formula A = lg(I0 / I); the values ​​of m and n are obtained using the equation lgA = mlgλ + n; and φ = γk2 is used to obtain the absorbance A of the sample at different wavelengths. 4 m -4 Obtain the average particle size φ (μm) of suspended matter in the sample to be tested, by N=10 13+n βk1 -1 k2 -16 γ -5 m 16 The number of suspended particles N (p / L) in the sample to be tested was obtained by using c = 0.524 × 10⁻⁶. 1+n βρk1 -1 k2 -4 γ -2 m 4 The suspended solids content c (mg / L) in the sample to be tested is obtained by T = βk3A 650nm Obtain the turbidity T (NTU) of the sample to be tested; where γ is the relative refractive index of the suspended matter in the sample to be tested, γ = r / r0; m and n are the slope and intercept of the linear regression equation lgA~lgλ, respectively; k1, k2, and k3 are the model correction coefficients obtained by measuring 200 NTU of formazan standard turbidity solution, A 650nm The absorbance of the sample under test is 650 nm.

[0008] Preferably, it also includes a dynamic measurement method, which first executes process S1a, and then inputs the start time, period (min) and duration (h) of the dynamic measurement; the period includes processes S1a-S2a, and the period is repeated cyclically until the duration is reached.

[0009] Preferably, the different wavelengths include six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm.

[0010] Preferably, distilled water is used as the sample to be tested, and process S2 is performed to obtain the light intensity I0 of the distilled water.

[0011] Preferably, the preparation method of the 200 NTU formalin standard turbidity solution is as follows: 5.00 mL of 1.00% hydrazine sulfate solution and 5.00 mL of 10.00% hexamethylenetetramine solution are mixed evenly to obtain a first solution, which is then allowed to stand at 25 ± 3 °C for 24 h. Distilled water is added to the first solution for dilution, and the mixture is stirred evenly to obtain a second solution, the total volume of which is 100 mL. 50 mL of the second solution is pipetted into a 100 mL volumetric flask and diluted to the 100 mL mark with distilled water. The transmitted light intensity I0 of the distilled water and the transmitted light intensity I of the 200 NTU formalin standard turbidity solution are obtained according to S2. The absorbance A of the 200 NTU formalin standard turbidity solution at different wavelengths is obtained using the formula A = lg(I0 / I). The values ​​of m and n are obtained using the equation lgA = mlgλ + n. The values ​​of m and n are obtained using the formula k1 = 2.09 × 10⁻⁶. (1+n) k2 = -1.23m, k3 = 200 / A 650nm Calculate k1, k2, and k3 respectively.

[0012] This invention also provides an automatic suspension detection device, applied to the aforementioned automatic suspension detection method, comprising an instrument housing and a sample cell, a lower-level circuit board, and an upper-level circuit board disposed within the instrument housing; the lower-level circuit board is electrically connected to the upper-level circuit board; one end of the sample cell is connected to an LED light source, and the other end is connected to a multi-channel visible light sensor; both the LED light source and the multi-channel visible light sensor are connected to the lower-level circuit board; the upper-level circuit board has a first communication interface and a second communication interface, the first communication interface being electrically connected to the lower-level circuit board, and the second communication interface being electrically connected to the upper-level circuit board; the instrument housing has an inlet and an outlet, the outlet being connected to the sample cell; and a delivery pump is also included, one end of which is connected to the inlet, and the other end of which is connected to the sample cell.

[0013] Preferably, the lower-level circuit board comprises a voltage regulator circuit, a microcontroller, a sensor interface circuit, a TTL-RS232 conversion circuit, a delivery pump control board, and a light source control circuit; the light source control circuit is electrically connected to the LED light source; the microcontroller is connected to the multi-channel visible light sensor through a sensor interface, and the sensor interface circuit is located between the sensor interface and the microcontroller; the delivery pump control board is electrically connected to the delivery pump, and the microcontroller is electrically connected to the delivery pump control board through the delivery pump control circuit; the microcontroller is also electrically connected to the first communication interface; the lower-level circuit board is electrically connected to the upper-level circuit board through a serial communication interface, and the microcontroller in the lower-level circuit board is electrically connected to the serial communication interface through a TTL-RS232 conversion circuit.

[0014] Preferably, the light source control circuit includes a light source operating circuit adjusting potentiometer, a reference voltage regulator circuit, a light source switch control circuit, a light source drive circuit, and a light source interface connected in sequence, wherein the light source interface is electrically connected to the LED light source; the microcontroller is connected to the light source switch control circuit. The instrument housing also has an operation panel with a touch screen display.

[0015] Preferably, the sample cell is a quartz tube closed at both ends, the inner diameter of the quartz tube is 10-15 mm and the length is 10-30 mm; a sample outlet connecting pipe and a sample inlet connecting pipe are connected to the side wall of the quartz tube, one end of the sample inlet connecting pipe is connected to the inner cavity of the quartz tube and the other end is connected to the delivery pump pipe; one end of the sample outlet connecting pipe is connected to the inner cavity of the quartz tube and the other end is connected to the sample outlet.

[0016] By employing the above technical solutions, this invention has the following advantages and positive effects compared with the prior art:

[0017] 1. The automatic suspension detection device and method provided by this invention differ from the principle of traditional laser particle size analyzers that collect single-wavelength scattered light information from multiple angles. The method proposed in this invention is the first to use ordinary LED white light source to illuminate the sample and use a miniature optical sensor to collect multi-wavelength transmitted light information. It establishes a mathematical relationship between absorbance and wavelength, particle and medium property parameters, and realizes instantaneous detection of suspension with high sensitivity and a detection limit of only 1 mg / L.

[0018] 2. The automatic suspension detection device and method provided by the present invention has a simple structure, is lightweight and compact, adopts touch screen operation, has a clear interface, intuitive results, and is easy to operate. Non-professionals can use it anytime and anywhere. It can meet the requirements of bulk sample detection as well as real-time and online detection.

[0019] 3. The automatic suspension detection device and method provided by the present invention can simultaneously obtain statistically significant measurements of particle size, particle number, suspended matter mass, turbidity, etc., with an error of less than 20%. It is suitable for various liquid media such as water, alcohol, and oil, and has broad application prospects in water quality detection, production process quality control, new material synthesis, cell culture and growth, wastewater treatment and other fields.

[0020] 4. The automatic suspension detection device and method provided by the present invention are equipped with network and communication interfaces, which facilitates connection with printers, satellite positioning and wireless network systems to develop real-time data transmission functions. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the automatic suspension detection device provided by the present invention;

[0022] Figure 2 This is a rear view of the automatic suspension detection device provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the lower-level circuit board structure of the automatic suspension detection device provided by the present invention.

[0024] Figure 4 The flowchart of the lower-level machine working program of the automatic suspension detection device provided by the present invention;

[0025] Figure 5 The flowchart of the host computer operation program of the automatic suspension detection device provided by the present invention;

[0026] Figure 6 This is a diagram of the operation panel of the automatic suspension detection device provided by the present invention;

[0027] Figure 7 The result diagram of the automatic suspension detection device provided by the present invention for the dynamic measurement of the silver chloride formation reaction is shown.

[0028] in:

[0029] 1—Instrument housing; 2—Upper computer circuit board; 3—USB interface; 4—Multi-channel visible light sensor; 5—Lower computer circuit board; 6—Peristaltic pump; 7—Pump tube; 8—Sample cell; 9—Lithium battery; 10—LED light source; 11—Charging port; 12—Power switch; 13—Sample inlet; 14—Sample outlet; 15—Touch screen; 16—Lower computer 24V input interface; 17—Voltage regulator circuit; 18—Microcontroller; 19—TTL and RS232 conversion circuit; 20—Sensor interface circuit; 21—Serial communication interface; 22—Reference voltage regulator circuit; 23—Light source working circuit adjustment potentiometer; 24—Light source drive circuit; 25—Light source interface; 26—Constant current and light source switch control circuit; 27—Peristaltic pump control circuit; 28—Lower computer program download port; 29—Sensor interface; 30—Peristaltic pump control board. Detailed Implementation

[0030] Referring to the accompanying drawings illustrating embodiments of the present invention, the invention will be described in more detail below. However, the invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are presented to achieve a full and complete disclosure and to enable those skilled in the art to fully understand the scope of the invention. In these drawings, the dimensions and relative dimensions of layers and regions may be enlarged for clarity.

[0031] This invention provides an automatic detection method for suspensions, including bulk sample measurement and dynamic measurement. The bulk sample measurement method involves turning on the instrument switch and, as shown in the attached... Figure 6Input the property parameters of the sample to be tested on the operation panel shown. These parameters include the refractive index r0 of the medium, density ρ (g / L), particle refractive index r, dilution factor β, and measurement wavelength λ (nm). Place the loose sample into a sample vial. Both the inlet 13 and outlet 14 on the instrument housing 1 are equipped with two silicone tubes, which are inserted into the sample vial. Select "Loose Sample Measurement" on the operation panel. The upper computer circuit board 2 will then display the relevant parameters. Figure 5 The host computer program transmits commands to the lower-level circuit board 5, the peristaltic pump 6 starts working, and transfers the sample to be tested from the sample vial to the sample cell 8; the LED light source 10 is turned on, and the sensor collects the transmitted light information of the sample to be tested in the sample cell 8, which is then transmitted through the lower-level circuit board 5. Figure 4 The lower-level computer program shown converts the transmitted light intensity I at six different wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm. Combined with the pre-measured transmitted light intensity I0 of distilled water, this is transmitted to the upper-level computer circuit. The upper-level computer program on circuit board 2 obtains the absorbance A of the sample at the six different wavelengths (450nm, 500nm, 550nm, 570nm, 600nm, and 650nm) using the formula A = lg(I0 / I); obtains the values ​​of m and n using the formula lgA = mlgλ + n; and obtains the values ​​of φ = γk2. 4 m -4 Obtain the average particle size φ (μm) of suspended matter in the sample to be tested, by N=10 13+n βk1 -1 k2 -16 γ -5 m 16 The number of suspended particles N (p / L) in the sample to be tested was obtained by using c = 0.524 × 10⁻⁶. 1+n βρk1 -1 k2 -4 γ -2 m 4 The suspended solids content c (mg / L) in the sample to be tested is obtained by T = βk3A 650nm Obtain the turbidity T (NTU) of the sample to be tested.

[0032] Wherein, γ is the relative refractive index of the suspended matter in the sample to be tested, γ=r / r0; m and n are the slope and intercept of the linear regression equation lgA~lgλ, respectively; k1, k2, and k3 are the model correction coefficients obtained by measuring 200NTU of formazan standard turbidity solution, and A650nm is the absorbance of the sample to be tested at a wavelength of 650nm.

[0033] The dynamic measurement method involves inserting both the inlet (13) and outlet (14) silicone tubes below the liquid surface in the reactor, as shown in the attached diagram. Figure 6On the control panel shown, input the refractive index r0, density ρ (g / L), particle refractive index r, dilution factor β, and measurement wavelength λ (nm) of the sample to be tested. In the dynamic measurement area, input the start time, period (min), and duration (h), and then tap... The host computer program and the slave computer program begin running. When the set start time is reached, the peristaltic pump 6 starts working, transferring the reaction solution to the sample cell 8, and the LED light source 10 is turned on to automatically measure the transmitted light intensity I of the reaction solution. When the measurement is completed, the peristaltic pump 6 and the LED light source 10 are turned off. The host computer program is as follows: Figure 5 The average particle size φ, particle number N, suspended solids content c, and turbidity T of the suspended solids in the reaction solution were calculated using the model. The absorbance A of the sample at six different wavelengths (450 nm, 500 nm, 550 nm, 570 nm, 600 nm, and 650 nm) was obtained using the formula A = lg(I0 / I). The values ​​of m and n were obtained using the equation lgA = mlgλ + n. The values ​​of m and n were obtained using the formula φ = γk2. 4 m -4 Obtain the average particle size φ (μm) of suspended matter in the sample to be tested, by N=10 13+n βk1 -1 k2 -16 γ -5 m 16 The number of suspended particles N (p / L) in the sample to be tested was obtained by using c = 0.524 × 10⁻⁶. 1+n βρk1 -1 k2 -4 γ -2 m 4 The suspended solids content c (mg / L) in the sample to be tested is obtained by T = βk3A 650nm Obtain the turbidity T (NTU) of the sample to be tested. The calculation result is displayed in real time in the corresponding position on the operation panel, and also in the corresponding space on the right. This process of injection, measurement, and calculation is repeated according to the set cycle until the time is reached, at which point the dynamic measurement ends.

[0034] like Figure 1-3The present invention also provides an automatic suspension detection device, applied to the above-mentioned automatic suspension detection method, comprising an instrument housing 1 and a sample cell 8, a lower-level circuit board 5, and an upper-level circuit board 2 disposed within the instrument housing 1; the lower-level circuit board 5 and the upper-level circuit board 2 are electrically connected; one end of the sample cell 8 is connected to an LED light source 10, which is a common LED lamp bead with an outer diameter of 3-5mm, an input voltage of 3-5V, a power of 0.2-0.5W, and a color temperature of 6300-6500K; the other end is connected to a multi-channel visible light sensor 4, which is an AS7262 type and can measure the light intensity of six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm. The LED light source 10 is connected to the lower-level computer circuit board 5 via an interface, and the multi-channel visible light sensor 4 is connected to the lower-level computer circuit board 5 via the lower-level computer program download port 28. The instrument housing 1 is provided with a sample inlet 13 and a sample outlet 14, and the sample outlet 14 is connected to the sample cell 8. It also includes a peristaltic pump 6, one end of which is connected to the sample inlet 13 and the other end is connected to the sample cell 8. The lower-level computer program is loaded into the lower-level computer microcontroller 18 via the download interface, and the upper-level computer program is loaded into the upper-level computer ROM via the USB interface 3. The upper-level computer circuit board 2 is provided with a sample information module, a sample measurement module, a dynamic measurement module, a model calibration module, a reference zeroing module, and a data management module.

[0035] The sample cell 8 is a quartz tube sealed at both ends. The inner diameter of the quartz tube is 10-15 mm and the length is 10-30 mm. An LED light source 10 and a sensor are respectively installed at both ends. An outlet connecting tube and an inlet connecting tube are connected to the side wall of the quartz tube. One end of the inlet connecting tube communicates with the inner cavity of the quartz tube, and the other end communicates with the peristaltic pump 6. One end of the outlet connecting tube communicates with the inner cavity of the quartz tube, and the other end communicates with the outlet 14. The inner diameter of both the inlet and outlet connecting tubes is 2 mm and the length is 15 mm.

[0036] The peristaltic pump 6 is a DC type with an input voltage of 12-24V, a power of 5-10W, a speed of 300-600rpm, and a flow rate of 20-120mL / min. It also includes a pump tube 7, which is a rubber tube with an inner diameter of 1-3mm and a wall thickness of 0.8mm. It has the characteristics of being wear-resistant, acid and alkali resistant, oil resistant, and organic solvent resistant.

[0037] The lower-level circuit board 5 comprises a voltage regulator circuit 17, a microcontroller 18, a sensor interface 29, a circuit 20, a TTL-RS232 conversion circuit 19, a peristaltic pump control board 30, and a light source control circuit. The voltage regulator circuit 17 supplies power to the entire module. The peristaltic pump control board 30 controls the peristaltic pump 6 to turn on during measurement and turn off when measurement is complete. The light source control circuit is electrically connected to the LED light source 10. The microcontroller 18 communicates with the multi-channel visible light sensor 4 via I / O. 2C sensor interface 29 connection, I 2 The sensor interface 29 circuit 20 is located between the sensor interface 29 and the microcontroller 18; the peristaltic pump control board 30 is electrically connected to the peristaltic pump 6, and the microcontroller 18 is electrically connected to the peristaltic pump control board 30 through the peristaltic pump control circuit 27; the microcontroller 18 is also electrically connected to the first communication interface; the lower-level circuit board 5 and the upper-level circuit board 2 are electrically connected through the serial communication interface 21, and the microcontroller 18 in the lower-level circuit board 5 is electrically connected to the serial communication interface 21 through the TTL and RS232 conversion circuit 19. The upper-level circuit board 2 is a commercially available industrial flat panel, consisting of an embedded system board and peripheral interfaces, including a network communication interface, an RS232 serial interface, and a USB interface 3, running WINCE 6.0 or later operating systems. The lower-level circuit board 5 is 15-20cm long and 8-15cm wide, with a power supply voltage of 12-24V, which is stepped down and regulated to power the microcontroller 18 and the LED light source 10.

[0038] The light source control circuit includes a light source operating circuit adjustment potentiometer 23, a reference voltage regulator circuit 22, a constant current and light source switch control circuit 26, a light source drive circuit 24, and a light source interface 25 connected in sequence. The light source interface 25 is electrically connected to the LED light source 10. The operating current of the LED light source 10 is changed by adjusting the sampling voltage value of the light source operating circuit adjustment potentiometer 23. The microcontroller 18 is connected to the constant current and light source switch control circuit 26, which controls the LED light source 10 to be turned on during measurement and turned off when the measurement is completed. The instrument housing 1 also has an operation panel with a touch screen 15. The touch screen 15 is a 7-10 inch TFT LCD with a resolution of 800×480 or higher and a brightness of 350-400 cd / m². 2 Contrast ratio 300-400:1, input voltage 12-24V, power 4-6W.

[0039] The instrument housing 1 is also equipped with a lithium battery 9, a charging port 11 and a power switch 12 that are electrically connected to the lithium battery 9. The lithium battery 9 has an input voltage of 110V or 220V, an output voltage of 12-24V, and a capacity of 2000-9000mAh.

[0040] The following examples illustrate this in detail:

[0041] Example 1: Reference Zeroing and Model Correction

[0042] Reference zeroing: Turn on instrument switch 12, and download the lower-level computer program ( Figure 4 The microcontroller 18 of the lower-level machine is loaded, and the upper-level machine program is transmitted via USB interface 3. Figure 5 After installing it into the host computer's CPU and restarting, the following error occurred: Figure 6The operation panel shown allows you to select sample property parameters, including: medium refractive index / density (r0 / ρ)—water (1.33 / 1000), particle refractive index (r)—organic matter (1.35), detection wavelength (λ)—650nm, and input the dilution factor (β) = 1. Take approximately 200mL of distilled water into the sample bottle, insert both the inlet (13) and outlet (14) silicone tubes into the sample bottle, and tap "Reference Zeroing." The peristaltic pump 6 will then transfer the distilled water to the sample cell 8. The LED light source 10 and sensor 4 will operate, collecting the transmitted light information of the distilled water in the sample cell 8, and transmitting it through the lower-level computer program (…). Figure 4 This is converted to the transmitted light intensity I0 at six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm, and automatically saved. Generally, a "reference zeroing" is performed after each power-on.

[0043] Model calibration: First, prepare a 200 NTU formalin standard turbidity solution. The method is as follows: Pipette 5.00 mL each of 1.00% hydrazine sulfate solution and 10.00% hexamethylenetetramine solution into a 100 mL volumetric flask, mix well, and let stand at 25±3℃ for 24 hours. Then dilute to the mark with distilled water, mix well, and then pipette 50 mL of the liquid into a 100 mL volumetric flask. Dilute to the mark with distilled water and mix well to obtain the 200 NTU formalin standard turbidity solution. Prepare fresh before use. Take approximately 200 mL of the 200 NTU formalin standard turbidity solution into a sample bottle. Insert both the inlet (13) and outlet (14) silicone tubes into the sample bottle. Then, touch the "Model Calibration" button on the operation panel. Figure 6 The peristaltic pump 6 transfers the standard turbidity solution to the sample cell 8. The LED light source 10 and sensor 4 operate, collecting the transmitted light information of the standard turbidity solution in the sample cell 8, and transmitting it through the lower-level computer program. Figure 4 This is converted into transmitted light intensity I at six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm, and transmitted to the host computer circuit 2, where it is processed by the host computer program. Figure 5 The absorbance A of the standard turbidity solution at six wavelengths (λ) was calculated using the formula A = lg(I0 / I). A linear fit was then performed on lgA to lgλ, yielding the fitting equation: lgA = -1.68lgλ + 0.705. Correction coefficients k1 = 4.12 and k2 = 2.07 were then calculated. The measured absorbance A at 650 nm was then used as the reference. 650nm =0.411. Calculate the correction factor k3 = 486. After confirmation, the calculation model will be automatically updated and saved for future measurement calculations. Model parameters may change with ambient temperature and generally need to be calibrated quarterly.

[0044] Example 2 Milk Powder Liquid Detection

[0045] Turn on instrument switch 12, and on the operation panel ( Figure 6 Select the sample property parameters, including: medium refractive index / density (r0 / ρ) - water (1.33 / 1000), particle refractive index (r) - organic matter (1.35), detection wavelength (λ) - 650nm, and input the dilution factor (β) = 1. First, perform "reference zeroing" according to the method in Example 1 to obtain the transmitted light intensity I0 of distilled water.

[0046] Disperse a small amount of milk powder in 500mL of hot water, stir, and cool to room temperature. Take approximately 200mL of the milk powder solution into a sample bottle. Insert both the inlet (sampling port 13) and outlet (sampling port 14) silicone tubes into the sample bottle. Touch the "Loose Sample Measurement" button on the operation panel. Figure 6 The peristaltic pump 6 transfers the milk powder liquid to the sample cell 8. The LED light source 10 and sensor 4 operate to collect the transmitted light information of the milk powder liquid in the sample cell 8, which is then processed by the lower-level computer program. Figure 4 This is converted into transmitted light intensity I at six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm, and transmitted to the host computer circuit 2, where it is processed by the host computer program. Figure 5 The absorbance A of the milk powder liquid at six wavelengths (λ) is calculated using the formula A = lg(I0 / I). A linear fit is then performed on lgA to lgλ, and the values ​​of m and n are determined from the fitted equation lgA = mlgλ + n. The host computer program then calculates the absorbance. Figure 5 According to φ=γk2 4 m -4 (γ=1.02, k2=2.07, the same below) The average particle size of the milk powder particles was calculated. Two repeated measurements yielded φ=0.303±0.003μm. Based on N=10 13+n βk1 -1 k2 -16 γ -5 m 16 (β=1, k1=4.12, the same below). The number of microparticles in the milk powder was calculated by two repeated measurements: N=(2.5±0.9)×10 13 p / L, according to c = 0.524 × 10 1+n βρk1 -1 k2 -4 γ -2 m 4 (ρ=1000g / L) Calculate the microparticle content of milk powder. Two repeated measurements yielded c=366±3mg / L. The absorbance A measured from the 650nm wavelength sample... 650nm =0.728 and T=βk3A 650nm(β=1, k3=486) The turbidity T of the milk powder solution was calculated to be 354 NTU, and the entire measurement process took less than 1 minute. However, using a Malvern nanoparticle size potentiometer to measure the same sample, the average particle size of the milk powder was found to be φ=0.325 μm, which took 10 minutes. The turbidity of the milk powder solution was measured to be 368 NTU using spectrophotometry (GB 13200-1991), which took 10 minutes. The content of milk powder particles was measured to be 312 mg / L using the traditional gravimetric method (GB11901-89), which took 4 hours. Therefore, compared with traditional methods, this method for detecting milk and other foods has good reproducibility, consistent results, and is more than ten times more efficient.

[0047] Example 3: Detection of suspended solids in wastewater

[0048] Turn on instrument switch 12, and on the operation panel ( Figure 6 Select the sample property parameters on the screen, specifically: medium refractive index / density (r0 / ρ) — water (1.33 / 1000), particle refractive index (r) — mixture (1.45), detection wavelength (λ) — 650nm, input dilution factor (β) = 1, first perform "reference zeroing" according to the method of Example 1, and obtain the transmitted light intensity I0 of distilled water.

[0049] Collect 500mL of sewage from a city. Take approximately 200mL of the sewage into a sample bottle. Insert both the inlet (sampling port 13) and outlet (sampling port 14) silicone tubes into the sample bottle. Tap the "Loose Sample Measurement" button on the operation panel. Figure 6 The peristaltic pump 6 transfers the water sample to the sample cell 8. The LED light source 10 and sensor 4 operate to collect the transmitted light information of the water sample in the sample cell 8, which is then processed by the lower-level computer program. Figure 4 This is converted into transmitted light intensity I at six wavelengths: 450nm, 500nm, 550nm, 570nm, 600nm, and 650nm, and transmitted to the host computer circuit 2, where it is processed by the host computer program. Figure 5 The absorbance A of the sample at six wavelengths (λ) is calculated using the formula A = lg(I0 / I), and a linear fit is performed on lgA ~ lgλ. The values ​​of m and n are determined by the fitting equation lgA = mlgλ + n. The host computer program then calculates the absorbance A of the sample at six wavelengths (λ). Figure 5 Using the same model as above, the average particle size of suspended solids in the water sample was calculated to be φ = 13.8 μm and the number of particles N = 2.5 × 10⁻⁶. 6The pH value, suspended solids content c = 3.43 mg / L, and turbidity T = 151 NTU were measured for this wastewater. Simultaneously, the average particle size φ of the suspended particles was measured to be 12.5 μm using a Malvern nanoparticle size potentiometer, the turbidity was measured to be 162 NTU using spectrophotometry (GB 13200-1991), and the suspended solids content was measured to be 3.95 mg / L using the conventional gravimetric method (GB11901-89). Therefore, compared with traditional methods, this device and method provide accurate and reliable results for detecting suspended solids in wastewater, achieving multi-functionality.

[0050] Example 4 Measurement of the silver chloride formation reaction

[0051] (1) Solution preparation

[0052] Solution A: Accurately weigh 0.060 g of sodium chloride and dissolve it in ~50 mL of distilled water, then dilute to 100 mL to obtain a 0.010 mM sodium chloride solution.

[0053] Solution B: Accurately weigh 0.170 g of silver nitrate and dissolve it in ~50 mL of distilled water, then dilute to 100 mL to obtain a 0.010 mM silver nitrate solution.

[0054] Solution C: Take 100 mL of distilled water into an Erlenmeyer flask, add 6.25 mL of concentrated nitric acid, shake well, and obtain a 1 M nitric acid solution.

[0055] (2) Dynamic measurement

[0056] Turn on the instrument switch 12 and touch the clock icon at the bottom of the control panel. Figure 6 Correctly set the current Beijing time, then select the sample property parameters, including: medium refractive index / density (r0 / ρ)—water (1.33 / 1000), detection wavelength (λ)—450nm, and custom input particle refractive index (r) = 2.07 and dilution factor (β) = 1. First, perform "reference zeroing" according to the method in Example 1 to obtain the transmitted light intensity I0 of distilled water. Then, in the "Dynamic Measurement" area of ​​the operation panel ( Figure 6 Enter the start time 20:03, the cycle period 1 (min) and the duration 1 (h).

[0057] Add 27 mL of distilled water, 5 mL of anhydrous ethanol, 15 mL of solution A, and 3 drops of solution C to a 100 mL volume in the brown reaction flask. Shake well. Insert the silicone tube at inlet 13 and outlet 14 into the reaction flask. Add 3 mL of solution B to the reaction flask and shake well immediately. Touch the control panel. ( Figure 6The host computer program and the slave computer program work together to run automatically. When the set start time of 20:05 is reached, the peristaltic pump 6 starts to transfer the reaction solution to the sample cell 8, and the LED light source 10 is turned on to automatically measure the transmitted light intensity I of the reaction solution. After the measurement is completed, the peristaltic pump 6 and the LED light source 10 are automatically turned off, and the host computer program ( Figure 5 The average particle size φ, number N, mass c, and turbidity T of the silver chloride microparticles generated in the reaction solution will be calculated according to the aforementioned model and method, and the results will be recorded in real time on the particle growth curve. Figure 7 The system performs sampling, measurement, and calculation cyclically at a set interval of 1 minute until a duration of 1 hour, i.e., at 21:03, at which point the dynamic measurement is complete. Tap the "USB" button on the operation panel. Figure 6 This allows you to browse or copy all dynamic measurement data of the reaction process.

[0058] from Figure 7 The growth curve of silver chloride particles shows that at room temperature (20℃), the mass of silver chloride particles gradually increases with increasing reaction time, reaching equilibrium after 30 min with a mass of 80.1 mg / L. This indicates that the growth of silver chloride particles is slow in the presence of 10% ethanol. Within 1 h, the number of silver chloride particles increased from 2.338 × 10⁻⁶. 13 p / L decreased to 1.32×10 12 The average particle size gradually increased from 0.139 μm to 0.487 μm, indicating that the silver chloride particles agglomerated and grew during the formation process. The turbidity of the silver chloride formation reaction solution increased from 14.6 NTU to 79.6 NTU within 1 hour, consistent with the increase in absorbance (A = 0.139 to A = 0.524) measured at 450 nm. Immediately after the dynamic measurement, the reaction solution was measured using a Malvern nanoparticle size potentiometer, yielding an average silver chloride particle size of 0.498 μm, consistent with the results obtained by this method. Furthermore, the theoretical silver chloride production amount calculated from the molar amounts of sodium chloride and silver nitrate was 86 mg / L, with an error of only -7% compared to the results measured by this method. Therefore, using this device for real-time dynamic measurement of the reaction solution is accurate and feasible.

[0059] It will be understood by those skilled in the art that the present invention can be implemented in many other specific forms without departing from its spirit or scope. Although embodiments of the invention have been described, it should be understood that the invention is not limited to these embodiments, and variations and modifications can be made by those skilled in the art within the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for automatic detection of a suspension, characterized in that, The method comprises the following steps: S1, input the property parameters of the sample to be tested, including medium refractive index r0, density p (g / L), particle refractive index r, and dilution factor β and measurement wavelength λ (nm); S2, the LED light source is turned on, and the sensor collects the transmission light information of the sample to be tested in the sample cell and converts it into transmission light intensity I at different wavelengths; S3, the average particle size φ (μm) of the suspended matter in the sample to be tested, the number of suspended particles N (p / L), the content of suspended matter c (mg / L), and the turbidity T (NTU) are calculated by the transmission light intensity I at different wavelengths; Obtain the transmission light intensity I0 of distilled water; Obtain the absorbance A of the sample to be tested at different wavelengths by the formula A = lg (I0 / I); Obtain the values of m and n by the equation lgA = mlgλ + n; By φ = γk2 4 m -4 Obtain the average particle size φ (μm) of suspended solids in the sample to be tested, by N = 10 13+n βk1 -1 k2 -16 γ -5 m 16 Obtain the number of suspended particles N (p / L) in the sample to be tested, by c = 0.524 × 10 1+n βρk1 -1 k2 -4 γ -2 m 4 Obtain the suspended solids content c (mg / L) in the sample to be tested, by T = βk3A 650nm Obtain the turbidity T (NTU) of the sample to be tested; wherein γ is the relative refractive index of the suspension of the sample to be measured, γ = r / r0; m and n are the slope and intercept of the linear regression equation of lgA~lgλ, respectively; k1, k2, and k3 are the model correction coefficients obtained by measuring the 200 NTU formazin standard turbidity liquid, A 650nm is the absorbance of the sample to be measured at a wavelength of 650 nm. It also includes a dynamic measurement method, which first executes process S1, and then inputs the starting time, period (min) and duration (h) of the dynamic measurement; The period includes processes S1-S2, and the period is repeated until the duration is reached; The different wavelengths include 450 nm, 500 nm, 550 nm, 570 nm, 600 nm and 650 nm; Take distilled water as the sample to be tested, perform process S2, and obtain the transmission light intensity I0 of the distilled water.

2. The method of claim 1, wherein the method comprises: The preparation method of the 200 NTU formazin standard turbidity liquid is as follows: 5.00 mL of 1.00% sulfuric acid hydrazine solution and 5.00 mL of 10.00% hexamethylenetetramine solution are mixed uniformly to obtain a first solution, which is placed at 25±3℃ for 24 h of reaction; Add distilled water to the first solution and mix uniformly to obtain a second solution, and the total amount of the second solution is 100 mL; Take 50 mL of the second solution into a 100 mL volumetric flask, and add distilled water to dilute to 100 mL scale; Obtain the transmission light intensity I0 of distilled water and the transmission light intensity I of the 200 NTU formazin standard turbidity liquid by S2; Obtain the absorbance A of the 200 NTU formazin standard turbidity liquid at different wavelengths by the formula A = lg (I0 / I); Obtain the values of m and n by the equation lgA = mlgλ + n; k1 = 2.09 x 10 (1+n) , k2 = -1.23 m, k3 = 200 / A 650nm k1, k2, k3 are calculated respectively.

3. The apparatus for automatically detecting a suspension liquid according to any one of claims 1 to 2, characterized by, It includes an instrument shell, a sample cell, a lower computer circuit board and an upper computer circuit board arranged in the instrument shell; the lower computer circuit board is electrically connected with the upper computer circuit board; one end of the sample cell is connected with an LED light source, and the other end is connected with a multi-channel visible light sensor; the LED light source and the multi-channel visible light sensor are connected with the lower computer circuit board; The upper computer circuit board is provided with a sample to be tested information program module, a scattered sample measurement program module, a dynamic measurement program module, a model correction program module, a reference zero correction program module and a data management program module; It also includes a first communication interface and a second communication interface, the first communication interface is electrically connected with the lower computer circuit board, and the second communication interface is electrically connected with the upper computer circuit board; The instrument shell is provided with a sample inlet and a sample outlet, and the sample outlet is connected with the sample cell; The instrument shell is provided with a sample inlet and a sample outlet, and the sample outlet is connected with the sample cell; The lower machine circuit board comprises a voltage stabilizing circuit, a single-chip microcomputer, a sensor interface circuit, a TTL-RS232 conversion circuit, a conveying pump control board and a light source control circuit; The light source control circuit is electrically connected with the LED light source; The single-chip microcomputer is connected with the multi-channel visible light sensor through a sensor interface, and the sensor interface circuit is arranged between the sensor interface and the single-chip microcomputer; the conveying pump control board is electrically connected with the conveying pump, and the single-chip microcomputer is electrically connected with the conveying pump control board through a conveying pump control circuit; the single-chip microcomputer is also electrically connected with the first communication interface; the lower machine circuit board is electrically connected with the upper machine circuit board through a serial communication interface, and the single-chip microcomputer in the lower machine circuit board is electrically connected with the serial communication interface through a TTL and RS232 conversion circuit.

4. The suspension automatic detection device according to claim 3, characterized in that, The light source control circuit comprises a light source working circuit adjusting potentiometer, a reference voltage stabilizing circuit, a light source switch control circuit, a light source driving circuit and a light source interface connected in sequence, and the light source interface is electrically connected with the LED light source; The single-chip microcomputer is connected with the light source switch control circuit; The instrument shell is further provided with an operation panel, and the operation panel is provided with a touch display screen.

5. The suspension automatic detection device according to claim 4, characterized in that, The sample cell is a quartz tube with both ends closed, and the inner cavity of the quartz tube has a diameter of 10-15 mm and a length of 10-30 mm; The side wall of the quartz tube is connected with a sample outlet communication pipe and a sample inlet communication pipe, one end of the sample inlet communication pipe is communicated with the inner cavity of the quartz tube, and the other end is communicated with the conveying pump pipe; one end of the sample outlet communication pipe is communicated with the inner cavity of the quartz tube, and the other end is communicated with the sample outlet.

Images