Automatic crystallization point measuring device

Abstract

The invention provides an automatic crystallization point measuring device. The automatic crystallization point measuring device comprises a control unit, a temperature control unit, a stirring unit, a data acquisition unit, a data management unit and a color touch liquid crystal display screen, the temperature control unit is used for automatically controlling the temperature of the sample within a preset temperature range; the stirring unit is used for stirring in the preheating and cooling process of the sample; the data acquisition unit acquires temperature data of a sample, and the control unit processes the temperature data according to a built-in judgment algorithm, generates a temperature-time curve and automatically judges a crystallization point according to a set threshold value; the data management unit is used for detecting data export and remote maintenance and storage; and the color touch liquid crystal display screen is used for parameter setting, real-time data display, temperature curve drawing and automatic judgment result display. According to the invention, full-automatic temperature control, automatic stirring and real-time data acquisition and processing technologies are adopted, so that the full-process automatic control of sample preheating, cooling, stirring and temperature curve drawing is realized, and the accurate capture of the crystallization transformation temperature is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of physical property detection instruments, and more specifically, to an automatic crystallization point determination device. Background Art

[0002] Most of the existing crystallization point determination instruments use manual observation or semi-automatic methods for temperature control and data recording. Operators need to closely monitor the temperature change during the cooling process of the sample and manually record the temperature value when the crystallization phenomenon appears. This method is not only cumbersome to operate, but also prone to errors due to subjective judgment of personnel and temperature fluctuations. At the same time, many instruments have problems such as slow response speed, large temperature fluctuations, and lag or errors in data processing in the temperature control system, making it difficult to accurately capture the phase change phenomenon that occurs in the sample in a short time. Summary of the Invention

[0003] In order to solve the above deficiencies of the prior art, the purpose of the present invention is to provide an automatic crystallization point determination device to overcome the defects in the prior art.

[0004] To achieve the above object, the present invention provides an automatic crystallization point determination device, comprising a control unit, a temperature control unit, a stirring unit, a data acquisition unit, a data management unit, and a color touch liquid crystal display screen; wherein, the temperature control unit includes a heater and a refrigeration module, the temperature control unit is electrically connected and signal-connected to the control unit, the temperature control unit is used to preheat and cool the sample, to automatically switch the heating and refrigeration functions according to the control of the control unit, and to adjust the heating and refrigeration power in real time according to the control of the control unit, and to automatically adjust the cooling rate when the sample temperature approaches the preset expected crystallization temperature, so as to achieve automatic temperature control of the sample within the expected crystallization temperature; the stirring unit is electrically connected and signal-connected to the control unit, the stirring unit is used to stir during the preheating and cooling processes of the sample, and to automatically start and stop stirring, automatically control the stirring time and stirring speed according to the control of the control unit, so as to make the temperature inside the sample uniform and there is no influence of local temperature difference during the cooling process of the sample; the data acquisition unit is electrically connected and signal-connected to the control unit, the data acquisition unit is used to acquire the temperature data of the sample, and transmit the temperature data to the control unit for processing, so that the control unit generates a temperature-time curve after processing the temperature data according to the built-in PID temperature control algorithm, and automatically determines the crystallization point according to the set threshold, so as to accurately capture the crystallization transformation temperature; the data management unit is electrically connected and signal-connected to the control unit, the data management unit is used to connect to an external printer and a computer through the communication interface of the control unit to achieve data export and remote maintenance; and to automatically save all detection data through the storage module built in the control unit; the color touch liquid crystal display screen is electrically connected and signal-connected to the control unit, the color touch liquid crystal display screen is used to set parameters through input operations, so that the control unit controls the temperature control unit, the stirring unit, and the data acquisition unit according to the parameters set by the color touch liquid crystal display screen.

[0005] Through the above technical solution, by adopting the full-automatic temperature control, automatic stirring, and real-time data acquisition and processing technologies, the temperature change of the sample during the cooling process is monitored and recorded in real time, and the temperature-time curve is automatically drawn, and the crystallization transformation temperature is automatically determined according to the preset algorithm, realizing the full-automatic control of the whole process of sample preheating, cooling, stirring, and temperature curve drawing, and ensuring the accurate capture of the crystallization transformation temperature.

[0006] As a further description of the automatic crystallization point determination device of the present invention, preferably, in the temperature-time curve, by detecting the temperature fluctuation within the detection time range and automatically determining the crystallization point according to the set threshold, it includes: triggering the determination when the slope of the temperature-time curve approaches 0; continuously detecting the stable value within the allowable range of temperature fluctuation; and outputting the crystallization point after the result correction value is compensated, so as to realize the automatic determination of the crystallization point; wherein, the threshold is the sum of the expected crystallization temperature and the result correction value.

[0007] Through the above technical solution, the closed-loop temperature control system based on the PID algorithm can maintain the temperature fluctuation of the specimen within the preset range, eliminate the problems of temperature overshoot or oscillation in traditional manual control, and provide a stable temperature field environment for the crystallization point detection. By triggering the determination when the slope of the temperature-time curve approaches 0, and adopting the dynamic threshold algorithm of the expected crystallization temperature + correction value, the system error caused by thermal inertia is automatically compensated, the deviation of the measurable result is reduced, and the determination result of the crystallization point is ensured to be more accurate.

[0008] As a further description of the automatic crystallization point determination device of the present invention, preferably, the two groups of heaters and refrigeration modules are electrically connected and signal-connected to the control unit through the PWM / GPIO interface respectively, so that the control unit controls the two groups of heaters and refrigeration modules to preheat and cool the specimen.

[0009] Through the above technical solution, two groups of heaters and refrigeration modules are configured, that is, a dual-channel detection system is adopted, and the two test units are independent of each other, and different specimens can be tested simultaneously. The heaters and refrigeration modules automatically preheat and cool the specimen through the control of the control unit to ensure stable temperature rise and fall and accurately capture the crystallization transition phenomenon.

[0010] As a further description of the automatic crystallization point determination device of the present invention, preferably, the control unit outputs a PWM signal according to the PID temperature control algorithm to control the on and off of the heaters and refrigeration modules to realize the automatic switching of heating and refrigeration functions. When heating is required, a positive signal is output according to the PID temperature control algorithm to drive the heaters. When refrigeration is required, a negative signal is output according to the PID temperature control algorithm to open the solenoid valve of the refrigeration module; and the control unit determines the preheating stage, cooling stage and critical temperature stage of the specimen according to the set specimen temperature range and expected crystallization temperature; where: in the preheating stage, the heaters work at full power and the refrigeration module is turned off; in the cooling stage, the power of the heaters is gradually reduced, the refrigeration module is started and the power of the refrigeration module is adjusted according to the PID temperature control algorithm; and in the critical temperature stage, the heaters are turned off, and the refrigeration module adjusts the power of the refrigeration module through a PWM signal to maintain a preset cooling rate to achieve automatic temperature control.

[0011] Through the above technical solution, the PID algorithm can be used to dynamically adjust the PWM duty cycle, realize the smooth switching between the heater and the refrigeration module, ensure that the temperature control accuracy reaches ±0.1 °C, and avoid temperature overshoot or oscillation. The heating and refrigeration modules are driven by forward / reverse signals respectively to achieve bidirectional temperature control with a fast response speed. In the preheating stage, the heater heats up rapidly at full power to shorten the initial heating time, and at the same time, the refrigeration module is turned off to reduce energy consumption; in the cooling stage, the PID algorithm dynamically adjusts the power decay curve of the heater and gradually starts the refrigeration module to achieve linear cooling and avoid abnormal crystallization of the sample caused by sudden temperature drop; in the critical temperature stage, the heater is turned off, and the refrigeration power is precisely controlled by PWM to maintain the constant temperature stability and ensure that the crystallization point detection environment meets the standard method.

[0012] As a further description of the automatic crystallization point determination device of the present invention, preferably, the temperature control unit further includes a buzzer, and the buzzer is electrically connected and signal-connected to the control unit through a digital power amplifier module, so that the control unit controls the buzzer to alarm for too high and too low sample temperatures to ensure the safety and stability of the detection process.

[0013] Through the above technical solution, by setting the functions of alarming for too high and too low temperatures, the safety and stability of the detection process are ensured. Compared with traditional devices, it performs more excellently in terms of temperature control accuracy and response speed. Through the input operation of the color touch liquid crystal display screen, the safety range of the temperature is manually input on the operation interface. If not manually set, the system automatically generates a default threshold according to the test standard (such as GB / T7533) to ensure the safety and stability of the detection process.

[0014] As a further description of the automatic crystallization point determination device of the present invention, preferably, the stirring unit includes two sets of automatic lifting stirring devices, and the automatic lifting stirring devices are driven by stepping motors. The two stepping motors are respectively electrically connected and signal-connected to the control unit, so that the control unit controls the two stepping motors according to the set parameters to realize the control of the stirring start, stirring stop, stirring time and stirring speed of the two sets of automatic lifting stirring devices.

[0015] Through the above technical solution, two sets of automatic lifting stirring devices and their stepping motors are configured, that is, a dual-channel detection system is adopted, and the two test units are independent of each other and can test different samples simultaneously. The automatic stirring of the automatic lifting stirring device ensures the uniform temperature inside the sample and reduces the detection error caused by local temperature differences. The automatic stirring not only improves the test accuracy but also solves the problem of detection deviation caused by uneven manual stirring, and improves the stability of the detection data.

[0016] As a further description of the automatic crystallization point determination device of the present invention, preferably, the data acquisition unit includes two sets of liquid bath temperature sensors, two sets of sample temperature sensors, and two sets of digital signal acquisition modules; each set of the liquid bath temperature sensors and the sample temperature sensors are respectively electrically connected and signal-connected to the digital signal acquisition module, and the digital signal acquisition module is electrically connected and signal-connected to the control unit, so as to collect temperature data in real time at a high frequency (for example, with a resolution of 0.01 °C) through the sample temperature sensors, perform digital processing on the high-frequency collected temperature data through the digital signal acquisition module, and further generate a temperature-time curve through the control unit for the high-frequency collected temperature data after digital processing.

[0017] Through the above technical solution, two sets of liquid bath temperature sensors, sample temperature sensors, and digital signal acquisition modules are configured, that is, high-frequency sampling and digital processing of real-time temperature data are realized through the built-in high-precision PT100 temperature sensor and high-speed digital signal acquisition module. A dual-channel detection system is adopted, and the two test units are independent of each other, and different specimens can be tested simultaneously. Traditional instruments usually only support single-channel detection, with low test efficiency. The dual-channel design not only shortens the test cycle, but also facilitates comparative analysis and improves the overall detection ability of the laboratory.

[0018] As a further description of the automatic crystallization point determination device of the present invention, preferably, the data management unit is electrically connected and signal-connected to an external printer through the RS232 interface of the control unit to realize historical data printing; the data management unit is electrically connected and signal-connected to an external computer through the USB circuit of the control unit to realize data export; the data management unit realizes data storage through the built-in DDR2 memory and SD card of the control unit.

[0019] Through the above technical solution, by equipping with multiple communication interfaces such as USB, RS232, and LAN, it supports the connection and data transmission of an external printer, and at the same time has a built-in storage function, automatically saves all detection data, is convenient for subsequent query, analysis, and archiving, and supports the query, printing, and export of historical data, meeting the requirements of the laboratory for data integrity and traceability. Compared with products that only provide basic data storage functions, this embodiment is more perfect in terms of data management and traceability.

[0020] As a further description of the automatic crystallization point determination device of the present invention, preferably, the color touch liquid crystal display screen is also used to display temperature data in real time, draw a temperature-time curve, and display the automatic determination result; the color touch liquid crystal display screen sets parameters through input operations, including sample name, expected crystallization temperature, sample temperature range, cooling rate, stirring start temperature, stirring stop condition, stirring speed, allowable temperature fluctuation range, and result correction value.

[0021] Through the above technical solution, the color touch liquid crystal display screen not only ensures high data acquisition accuracy and fast response, but also greatly optimizes the user operation experience and data management method through the graphical interface.

[0022] As a further description of the automatic crystallization point determination device of the present invention, preferably, the control unit is an embedded control system using an ARM processor to achieve automatic coordinated control of the dual-channel temperature control unit, stirring unit, and data acquisition unit.

[0023] Through the above technical solution, a high-performance microprocessor based on an embedded system is used as the core, integrating functions such as temperature control, stirring, data acquisition and processing, and display control. The control unit realizes automatic coordination between the unit modules of the dual channels, and the entire detection process does not require manual intervention. While improving the degree of automation, it ensures that the data processing speed and accuracy far exceed those of traditional instruments.

[0024] The beneficial effects of the present invention are as follows: 1) The present invention adopts fully automatic temperature control, automatic stirring, and real-time data acquisition and processing technologies to monitor and record the temperature changes of the specimen during the cooling process in real time, and automatically draw the temperature-time curve. It automatically determines the crystallization transition temperature according to the preset algorithm, realizing the full-process automatic control of specimen preheating, cooling, stirring, and temperature curve drawing, and ensuring the accurate capture of the crystallization transition temperature. It has obvious advantages in terms of automation level, temperature control accuracy, and data processing ability compared with some existing crystallization point instruments on the market that still rely on semi-automatic or manual operations, and can effectively solve the detection error problems caused by traditional instruments due to cumbersome operations, unstable temperature control, and lag or errors in temperature control response and data processing. 2) The present invention integrates a high-precision temperature sensor and a digital signal acquisition module, uses the built-in determination algorithm to automatically analyze temperature fluctuations, accurately determines the crystallization point of the specimen, and improves the detection repeatability and stability. 3) The present invention adopts a dual-channel independent test design, which can simultaneously measure two specimens, thus greatly improving the detection efficiency. With the dual-channel independent test, the two test units are independent of each other and can simultaneously test different specimens. Traditional instruments usually only support single-channel detection, with low test efficiency. The dual-channel design not only shortens the test cycle but also facilitates comparative analysis and improves the overall detection ability of the laboratory. 4) The present invention fully considers the requirements of multiple national standards such as GB / T7533-1993, GB / T3145-2023, GB / T13255.2-2009, GB / T3710-2009, GB / T618-2006, GB / T1663-2001, etc., and has a wide range of applications. It is applicable to the crystallization point detection of chemical products and organic reagents, and is mainly used for the crystallization point detection of organic chemical products, benzene, industrial caprolactam, industrial phenol, phenol, plasticizers, etc. 5) The present invention adopts a large-size color liquid crystal touch screen, supports parameter setting, real-time monitoring of the test process, real-time data display, historical record query, external printing, and U disk data export, with intuitive operation and convenient maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the overall structural block diagram of the automatic crystallization point determination device of the present invention; Figure 2 is the structural block diagram of the control unit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to further understand the structure, features, and other purposes of the present invention, the following is a detailed description with reference to the attached preferred embodiments and accompanying drawings. The embodiments described by these drawings are only used to illustrate the technical solutions of the present invention and do not limit the present invention.

[0027] As the first embodiment of the present invention, as Figure 1As shown in the figure, the present invention provides an automatic crystallization point determination device, which includes a control unit 1, a temperature control unit 2, a stirring unit 3, a data acquisition unit 4, a data management unit 5 and a color touch liquid crystal display screen 6. Each unit module works together to ensure that the detection process is fully automatic and the data is accurate.

[0028] The control unit 1 uses a high-performance microprocessor (ARM) with an embedded operating system as the core, integrating functions such as temperature control, stirring, data acquisition and processing, and display control, to achieve automatic coordination among the modules of the temperature control unit 2, the stirring unit 3, the data acquisition unit 4, the data management unit 5 and the color touch liquid crystal display screen 6. This makes the entire detection process of automatic crystallization point determination without manual intervention. While improving the degree of automation, it ensures that the data processing speed and the accuracy of automatic determination far exceed those of traditional manual recording methods and instruments, greatly reducing the operation difficulty and human error.

[0029] The temperature control unit 2 includes a heater and a refrigeration module. The temperature control unit 2 is electrically connected and signal-connected to the control unit 1. The temperature control unit 2 is used to preheat and cool the sample, to automatically switch the heating and refrigeration functions according to the control of the control unit 1, and to adjust the heating and refrigeration power in real time according to the control of the control unit 1, ensuring that the temperature drops at a predetermined rate, and automatically adjusting the cooling rate when the sample temperature approaches the preset expected crystallization temperature, so as to achieve automatic temperature control of the sample within the expected crystallization temperature, ensuring a stable temperature, and thus accurately capturing the crystallization point. The value of the expected crystallization temperature is determined by test standards (such as GB / T7533) or empirical data. Through the control of the control unit 1, the temperature control unit 2 can accurately control the cooling process, reduce the influence of human operation errors, thereby obtaining more reliable and repeatable results, and improving the determination efficiency and degree of automation.

[0030] The stirring unit 3 is electrically connected and signal-connected to the control unit 1. The stirring unit 3 is used to stir during the preheating and cooling processes of the sample, and to automatically start and stop stirring, automatically control the stirring time and stirring speed according to the control of the control unit 1, so as to make the temperature inside the sample uniform, ensuring that there is no influence of local temperature difference during the cooling process of the sample, effectively solving the detection deviation problem caused by uneven manual stirring of traditional instruments, and significantly improving the stability and accuracy of the detection data.

[0031] The data acquisition unit 4 is electrically and signal-connected to the control unit 1. The data acquisition unit 4 is used to collect the temperature data of the sample and transmit the temperature data to the control unit 1 for processing. The control unit 1 processes the temperature data according to the built-in PID temperature control algorithm to generate a temperature-time curve, and automatically determines the crystallization point based on the set threshold value to accurately capture the crystallization transition temperature. The PID temperature control algorithm is implemented by combining the cooling curve method with the existing PID temperature control algorithm (refer to Chapter 3, PID Control Principle in "Process Control: Modeling, Design, and Simulation").

[0032] The data management unit 5 is electrically and signal-connected to the control unit 1. The data management unit 5 is used to connect to an external printer and a computer through the communication interface of the control unit 1 to achieve data export and remote maintenance. The data management unit 5 is also used to automatically save all detection data through the storage module built in the control unit 1. All detection data are automatically stored, and support historical data query, printing, and export, which is convenient for subsequent query, analysis, and archiving, meeting the requirements of the laboratory for data management, integrity, and traceability.

[0033] The color touch liquid crystal display screen 6 is electrically and signal-connected to the control unit 1. The color touch liquid crystal display screen 6 is used to set parameters through input operations. The control unit 1 controls the temperature control unit 2, the stirring unit 3, and the data acquisition unit 4 according to the parameters set by the color touch liquid crystal display screen 6. The parameters set by the color touch liquid crystal display screen 6 through input operations include sample name, expected crystallization temperature, sample temperature range, cooling rate, stirring start temperature, stirring stop condition, stirring speed, allowable temperature fluctuation range, result correction value, etc. Preferably, the color touch liquid crystal display screen 6 uses a color liquid crystal touch screen of more than 10.4 inches as the operation platform, with an intuitive and friendly interface design, supporting parameter setting, real-time monitoring of the test process, data query, external printing, and U disk data export, with intuitive operation and convenient maintenance. The user can conveniently view the real-time temperature data of the measurement process, the drawn temperature-time curve, and the crystallization point determination result displayed graphically through the color touch liquid crystal display screen 6.

[0034] This embodiment adopts fully automatic temperature control, automatic stirring, and real-time data acquisition and processing technologies to monitor and record the temperature change of the sample during the cooling process in real time, automatically draw the temperature-time curve, and automatically determine the crystallization transition temperature according to the preset algorithm, realizing the full-process automatic control of sample preheating, cooling, stirring, and temperature curve drawing, and ensuring the accurate capture of the crystallization transition temperature.

[0035] As the second embodiment of the present invention, the control unit 1 processes the temperature data of the specimen according to the built-in PID temperature control algorithm to generate a temperature-time curve. In the temperature-time curve, the crystallization point is automatically determined by detecting the temperature fluctuation (such as ±0.02 °C) within the detection time range and based on a set threshold value, including: triggering the determination when the slope of the temperature-time curve approaches 0; continuously detecting the stable value within the allowable range of temperature fluctuation (such as ±0.1 °C); outputting the crystallization point after compensating with the result correction value (such as +0.05 °C) to achieve automatic determination of the crystallization point. The above threshold value = expected crystallization temperature + result correction value. For example, if the expected crystallization temperature is 45 °C and the correction value is +0.05 °C, then the threshold value is 45.05 °C. The allowable range of temperature fluctuation, the expected crystallization temperature, and the result correction value are all preset through the input operation of the color touch liquid crystal display screen 6.

[0036] The closed-loop temperature control system based on the PID algorithm in this embodiment can maintain the temperature fluctuation of the specimen within the preset range, eliminating the problems of temperature overshoot or oscillation in traditional manual control, and providing a stable temperature field environment for the crystallization point detection. By triggering the determination when the slope of the temperature-time curve approaches 0 and adopting the dynamic threshold algorithm of expected crystallization temperature + correction value, the system error caused by thermal inertia is automatically compensated, the deviation of the measurable result is reduced, and the determination result of the crystallization point is ensured to be more accurate.

[0037] As the third embodiment of the present invention, as Figure 2 shown, preferably, the temperature control unit 2 includes two groups of heaters (heating rods) and a refrigeration module (compressor), and relies on the metal bath thermostat technology to achieve rapid temperature response. The two groups of heaters and the refrigeration module are respectively electrically connected and signal-connected to the control unit 1 through the PWM / GPIO interface, so that the control unit 1 controls the two groups of heaters and the refrigeration module to preheat and cool the specimen. This embodiment configures two groups of heaters, the refrigeration module and its metal bath thermostat, that is, adopts a dual-channel detection system, and the two test units are independent of each other and can test different specimens simultaneously.

[0038] As the fourth embodiment of the present invention, the control unit 1 outputs a PWM signal according to the PID temperature control algorithm to control the on-off of the heaters and the refrigeration module to achieve automatic switching between heating and refrigeration functions. When heating is required, a positive signal is output according to the PID temperature control algorithm to drive the heater; when refrigeration is required, a negative signal is output according to the PID temperature control algorithm to open the solenoid valve of the refrigeration module.

[0039] Meanwhile, the control unit 1 determines the preheating stage, cooling stage, and critical temperature stage of the specimen according to the set specimen temperature range and expected crystallization temperature. Among them: in the preheating stage, the heater operates at full power and the refrigeration module is turned off; in the cooling stage, the power of the heater gradually decreases, the refrigeration module is started, and the power of the refrigeration module is adjusted according to the PID temperature control algorithm; in the critical temperature stage, the heater is turned off, and the power of the refrigeration module is adjusted by the PWM signal to maintain the preset cooling rate to achieve automatic temperature control. The cooling rate is dynamically adjusted according to the "gradually decreasing temperature" parameter (such as 2°C / min) in the test method through the PID temperature control algorithm, so that the error between the actual cooling rate and the preset value is ≤ ±0.5°C / min. The above specimen temperature range, expected crystallization temperature, and cooling rate are all preset through the input operation of the color touch liquid crystal display screen 6.

[0040] In this embodiment, the PID algorithm is used to dynamically adjust the PWM duty cycle, realize the smooth switching of the heater and the refrigeration module, ensure that the temperature control accuracy reaches ±0.1°C, and avoid temperature overshoot or oscillation. The heating and refrigeration modules are driven by positive / negative signals respectively to achieve two-way temperature control with a fast response speed. In the preheating stage, the heater rapidly heats up at full power, shortening the initial heating time, and at the same time turning off the refrigeration module to reduce energy consumption; in the cooling stage, the PID algorithm dynamically adjusts the power decreasing curve of the heater and gradually starts the refrigeration module to achieve linear cooling and avoid abnormal crystallization of the specimen caused by sudden temperature drop; in the critical temperature stage, the heater is turned off, and the refrigeration power is precisely controlled by PWM to maintain the constant temperature stability and ensure that the crystallization point detection environment meets the standard method.

[0041] As the fifth embodiment of the present invention, as Figure 2 shown, the temperature control unit 2 further includes a buzzer, and the buzzer is electrically connected and signal-connected to the control unit 1 through a digital power amplifier module, so that the buzzer is controlled by the control unit 1 to alarm for too high and too low specimen temperatures to ensure the safety and stability of the detection process. The temperature setting for the buzzer alarm is manually input into the safety range on the operation interface through the input operation of the color touch liquid crystal display screen 6. If not manually set, the system automatically generates a default threshold according to the test standard (such as GB / T7533). This embodiment ensures the safety and stability of the detection process by setting the functions of too high and too low temperature alarms. Compared with traditional equipment, it performs more excellently in terms of temperature control accuracy and response speed.

[0042] As the sixth embodiment of the present invention, as Figure 2As shown in the figure, the stirring unit 3 includes two sets of automatically lifting stirring devices (stirrers). Both sets of the automatically lifting stirring devices are driven by stepping motors, and the two stepping motors are electrically connected and signal-connected to the control unit 1 respectively. The control unit 1 controls the two stepping motors according to the set parameters, thereby realizing the control of the stirring start, stirring stop, stirring time and stirring speed of the two sets of automatically lifting stirring devices. Specifically, it includes: the control unit controls the stirring unit to automatically start stirring according to the set stirring start temperature, controls the stirring unit to automatically stop stirring and the stirring time according to the set stirring stop condition, and controls the stirring speed of the stirring unit according to the set stirring speed. The stirring start temperature, stirring stop condition and stirring speed are all set through the input operation of the color touch liquid crystal display screen. Among them, the stirring start temperature is set to a set temperature difference higher than the expected crystallization temperature, such as 5°C, to ensure that the temperature inside the sample is uniform during the triggering of the crystallization point determination process and the obtained results are more accurate. The stirring stop condition is set to the detection time range and temperature fluctuation threshold. The stirring speed is set to 60 times per minute and can be adjusted according to the actual situation, realizing the automation of the stirring process.

[0043] In this embodiment, two sets of automatically lifting stirring devices and their stepping motors are configured, that is, a dual-channel detection system is adopted, and the two test units are independent of each other and can test different samples simultaneously. The automatic stirring of the automatically lifting stirring device ensures the uniform temperature inside the sample and reduces the detection error caused by local temperature differences. The automated stirring not only improves the test accuracy but also solves the problem of detection deviation caused by uneven manual stirring, significantly improving the stability of the detection data.

[0044] As the seventh embodiment of the present invention, as Figure 2 shown, the data acquisition unit 4 includes two sets of liquid bath temperature sensors, two sets of sample temperature sensors and two sets of digital signal acquisition modules. Each set of the liquid bath temperature sensors and the sample temperature sensors are electrically connected and signal-connected to the digital signal acquisition module respectively, and the digital signal acquisition module is electrically connected and signal-connected to the control unit 1. The temperature data is collected in real time at a high frequency (for example, with a resolution of 0.01°C) through the sample temperature sensor, and the high-frequency collected temperature data is digitally processed by the digital signal acquisition module, and then the digitally processed temperature data generates a temperature-time curve through the control unit 1.

[0045] This embodiment configures two sets of liquid bath temperature sensors, sample temperature sensors, and digital signal acquisition modules. That is, through the built-in high-precision PT100 temperature sensors and high-speed digital signal acquisition modules, high-frequency sampling and digital processing of real-time temperature data are achieved. A dual-channel detection system is adopted, and the two test units are independent of each other, enabling the simultaneous testing of different specimens. Traditional instruments usually only support single-channel detection, resulting in low testing efficiency. The dual-channel design not only shortens the testing cycle but also facilitates comparative analysis and improves the overall detection ability of the laboratory.

[0046] As the eighth embodiment of the present invention, as Figure 2 shown, the data management unit 5 is electrically connected and signal-connected to an external printer through the RS232 interface of the control unit 1 to achieve the printing of historical data. The data management unit 5 is electrically connected and signal-connected to an external computer through the USB circuit of the control unit 1 to achieve data export. The data management unit 5 realizes data storage through the built-in DDR2 memory and SD card of the control unit 1.

[0047] This embodiment is equipped with multiple communication interfaces such as USB, RS232, and LAN, supports the connection of an external printer and data transmission, and at the same time has a built-in storage function to automatically save all detection data, facilitating subsequent query, analysis, and archiving. It also supports the query, printing, and export of historical data, meeting the laboratory's requirements for data integrity and traceability. Compared with products that only provide basic data storage functions, this embodiment is more perfect in terms of data management and traceability.

[0048] The testing process of the above automatic crystallization point measuring device is as follows: In the preheating stage, the temperature control unit 2 starts heating and preheats the sample at the heating rate input on the color touch liquid crystal display screen 6. The stirring unit 3 starts automatically and stirs the sample at the stirring speed input on the color touch liquid crystal display screen 6 to ensure uniform temperature distribution. The data acquisition unit 4 monitors the temperature of the sample in real time and transmits the data to the control unit 1. In the cooling stage, when the temperature of the sample reaches the starting temperature input on the color touch liquid crystal display screen 6, the temperature control unit 2 automatically switches to the refrigeration mode and cools down at the cooling rate input on the color touch liquid crystal display screen 6. The data acquisition unit 4 continuously monitors the temperature of the sample in real time and transmits the data to the control unit 1. When the temperature of the sample approaches the expected crystallization temperature, the control unit 1 automatically adjusts the cooling rate to capture the crystallization point more precisely. During this process, the stirring unit 3 keeps stirring to avoid the influence of local temperature difference on the detection result. The data acquisition unit 4 continuously collects the temperature data, and the control unit 1 generates a temperature-time curve according to the built-in PID temperature control algorithm. When the detected temperature change conforms to the characteristics of the crystallization point, the control unit 1 automatically determines the crystallization point and records the data. After the detection is completed and the control unit 1 determines the crystallization point, the temperature control unit 2 stops refrigerating, and the stirring unit 3 automatically stops stirring. The data management unit 5 automatically saves the detection data (including the temperature curve, crystallization point value, etc.) to the built-in storage module. Subsequently, the detection result can be viewed through the color touch liquid crystal display screen 6, or the data can be exported and printed by connecting an external printer or computer through the data management unit 5.

[0049] It should be noted that the above-mentioned invention content and specific implementation manners are intended to prove the practical application of the technical solutions provided by the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make various modifications, equivalent replacements or improvements within the spirit and principle of the present invention. The protection scope of the present invention shall be subject to the appended claims.

Claims

1. An automatic crystallization point measuring device, characterized in that: It comprises a control unit (1), a temperature control unit (2), a stirring unit (3), a data acquisition unit (4), a data management unit (5) and a color touch liquid crystal display screen (6); wherein: The temperature control unit (2) comprises a heater and a cooling module. The temperature control unit (2) is electrically and signal-connected to the control unit (1). The temperature control unit (2) is used to preheat and cool the sample, to automatically switch between heating and cooling functions according to the control of the control unit (1), and to adjust the heating and cooling power in real time according to the control of the control unit (1). When the sample temperature approaches a preset expected crystallization temperature, the cooling rate is automatically adjusted to achieve automatic temperature control of the sample within the expected crystallization temperature. The stirring unit (3) is electrically and signal-connected to the control unit (1), and is used to stir the sample during preheating and cooling, and to automatically start and stop stirring, and automatically control stirring time and stirring speed according to the control of the control unit (1), so as to achieve uniform temperature inside the sample and eliminate the influence of local temperature difference during cooling of the sample; The data acquisition unit (4) is electrically and signal-connected to the control unit (1). The data acquisition unit (4) is used to collect temperature data of the sample and transmit the temperature data to the control unit (1) for processing, so that the control unit (1) processes the temperature data according to a built-in PID temperature control algorithm to generate a temperature-time curve, and automatically determines the crystallization point according to a set threshold value, so as to achieve accurate capture of the crystallization transition temperature; The data management unit (5) is electrically and signal-connected to the control unit (1), and the data management unit (5) is used to connect to an external printer and a computer via a communication interface of the control unit (1) to achieve data export and remote maintenance; and is used to automatically save all detection data via a storage module built into the control unit (1); The color touch liquid crystal display screen (6) is electrically and signal-connected to the control unit (1). The color touch liquid crystal display screen (6) is used to set parameters through input operations, so that the control unit (1) controls the temperature control unit (2), the stirring unit (3) and the data acquisition unit (4) according to the parameters set by the color touch liquid crystal display screen (6).

2. The automatic crystallization point measuring device according to claim 1, characterized in that: In the temperature-time curve, the crystallization point is automatically determined by detecting the temperature fluctuation within the time range and according to the set threshold value, including: triggering the determination when the slope of the temperature-time curve approaches 0; continuously detecting the stable value within the allowable range of temperature fluctuation; and outputting the crystallization point after compensating the result correction value to realize automatic determination of the crystallization point; wherein the threshold value is the sum of the expected crystallization temperature and the result correction value.

3. The automatic crystallization point measuring device according to claim 1, characterized in that: The two groups of heaters and cooling modules are respectively electrically and signal-connected to the control unit (1) via a PWM / GPIO interface, so that the control unit (1) controls the two groups of heaters and cooling modules to preheat and cool the sample.

4. The automatic crystallization point measuring device according to claim 3, characterized in that: The control unit (1) outputs a PWM signal according to a PID temperature control algorithm to control the switches of the heater and the cooling module to realize automatic switching between heating and cooling functions. When heating is required, a positive signal is output according to the PID temperature control algorithm to drive the heater. When cooling is required, a reverse signal is output according to the PID temperature control algorithm to open the solenoid valve of the cooling module. In addition, the control unit (1) determines the preheating stage, the cooling stage and the critical temperature stage of the sample according to the set sample temperature range and the expected crystallization temperature. In particular, the preheating stage is when the heater works at full power and the cooling module is turned off. In the cooling stage, the heater power is gradually reduced, the cooling module is started and the power of the cooling module is adjusted according to the PID temperature control algorithm. In addition, the critical temperature stage is when the heater is turned off and the cooling module adjusts the power of the cooling module through the PWM signal to maintain a preset cooling rate to realize automatic temperature control.

5. The automatic crystallization point measuring device according to claim 1, characterized in that: The temperature control unit (2) also includes a buzzer, which is electrically and signal-connected to the control unit (1) via a digital power amplifier module, so that the control unit (1) controls the buzzer to alarm when the sample temperature is too high or too low, thereby ensuring a safe and stable detection process.

6. The automatic crystallization point measuring device according to claim 1, characterized in that: The stirring unit (3) comprises two groups of automatic lifting stirring devices, the automatic lifting stirring devices are driven by stepping motors, and the two groups of stepping motors are respectively electrically connected and signal-connected to the control unit (1), so that the control unit (1) controls the two groups of stepping motors according to set parameters, thereby realizing the control of the stirring start, stirring stop, stirring time and stirring speed of the two groups of automatic lifting stirring devices.

7. The automatic crystallization point measuring device according to claim 1, characterized in that: The data acquisition unit (4) comprises two groups of liquid bath temperature sensors, two groups of sample temperature sensors and two groups of digital signal acquisition modules; the liquid bath temperature sensors and the sample temperature sensors of each group are respectively electrically connected and signal-connected to the digital signal acquisition modules, and the digital signal acquisition modules are electrically connected and signal-connected to the control unit (1), so that temperature data can be acquired in real time and at high frequency by the sample temperature sensors, and the high-frequency acquired temperature data is digitally processed by the digital signal acquisition modules, so that the high-frequency acquired temperature data after digital processing is used to generate a temperature-time curve through the control unit (1).

8. The automatic crystallization point measuring device according to claim 1, characterized in that: The data management unit (5) is electrically connected and connected by signal to an external printer via the RS232 interface of the control unit (1) to achieve historical data printing; the data management unit (5) is electrically connected and connected by signal to an external computer via the USB circuit of the control unit (1) to achieve data export; the data management unit (5) achieves data storage via the built-in DDR2 memory and SD card of the control unit (1).

9. The automatic crystallization point measuring device according to claim 1, characterized in that: The color touch liquid crystal display screen (6) is also used to display temperature data in real time, draw temperature-time curves and automatically determine the display results; the color touch liquid crystal display screen (6) is used to set parameters including sample name, expected crystallization temperature, sample temperature range, cooling rate, stirring start temperature, stirring stop condition, stirring speed, temperature fluctuation allowable range and result correction value through input operation.

10. The automatic crystallization point measuring device according to claim 1, characterized in that: The control unit (1) is an embedded control system using an ARM processor to achieve automatic coordinated control of a dual-channel temperature control unit (2), a stirring unit (3) and a data acquisition unit (4).

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