Study On Timing Temperature Conctrltechnology Of Hot-stage Microscopy System

As the continuous development of China’s economy,medicine,chemical reagents,spices,printing and dyeing industries,the purity of organic crystal material in the production process,the quality of the product plays a vital role.Since the melting point of the organic crystalline material is an important parameter,it is an important means for analyzing the purity of the substance by measuring its melting point.The melting point of the current determination of the main use of thermal analysis method,the principle is: in the program control temperature,the physical properties of substances and temperature or time relationship.Therefore,the performance of temperature control is important for melting point measurements.This topic mainly studies the design of new micro-thermal analyzer,focusing on the design of timing temperature control system to improve the performance of micro-thermal analyzer.This paper designed the STM32 core of the digital system circuit and top-down software system,including RS232,USB and PC interface design,human-machine interface design and drawing design,the host computer software and multi-language version.After the comparison and analysis of many high-precision temperature acquisition schemes,the design,selection and shaping of the two pairs of thermocouples for the core of the collection are completed and the experimental design is made.The use of thermocouples can fundamentally solve the weak links of the current domestic hot stage,but it also brings many difficulties in all aspects of the design.This paper rejoins and completes the design of new power amplification system and temperature acquisition system.Aiming at the compensation accuracy of thermocouple,many selection experiments have been done.Pairs of thermocouple product is currently the first application in the domestic hot stage instrument.This paper analyzes and compares the general control algorithm suitable for the system.In the preset temperature,fuzzy PID control is used to realize the fast preset speed,very weak overshoot,small static error and improve the anti-jamming ability.In the linear heating step,the periodic step control method is adopted,and a method of tailoring the optimal timer step and period is proposed to realize the stepless rate.Finally,the experimental results show that the temperature control system is fast,the steady-state error is small,the preset-melting point is near,the heating rate is stable,the robustness is good,and the problem of high rate and stepless temperature rise is solved.The thermal analyzer developed in this paper has been mass production,its performance close to similar foreign products.