Dynamic Testing System Of Solid-liquid Solubility Based On Laser Intensity

Solubility is one of the important parameters to reflect the properties of reagent.The parameters are widely used in many fields such as medicine,chemistry and industrial production.However,the current measurement method of solid-liquid solubility parameter is not mature and perfect.The traditional methods such as balance method and dynamic method determine the reagent's dissolved balanced end by the human eye.The drawback is large error and low efficiency due to the human factors.Also,these traditional methods only can measure static system.An automatic dynamic solubility detection system with high precision and high efficiency is designed to solve the defects of traditional methods,which is of great practical significance to the solubility experiment in the field of chemical,medical and industrial production.So this paper presents an automatic dynamic solubility detection system based on the law of Lambert solution optical absorption.The system include a stable laser light irradiation,a sensitive photodiode detection and a computer dynamic acquisition system of temperature—time and light intensity—time.According to the key of this paper the content of this paper is as follows:First of all,we analyze the Lambert principle's basis and scope and the factors which causing the deviation of the Lambert law.Aiming at the key factors of influencing the measurement accuracy,we study the control algorithm and design the double closed-loop control model of the semiconductor laser with constant power.Based on the neural network PI control algorithm,the laser with constant power control algorithm is proposed and the effectiveness of the algorithm is verified by simulation.This part includes two points.One is the hardware circuit design of the laser constant power control system.The key of circuit is the PIC microcontroller.The other is the software program.Finally we meet the design requirements that power fluctuation is stable control and the precision is below 2.4%.Secondly,the hardware circuit and software program of the receiving system are studied and designed according to the system requirements for laser light intensity and temperature detection.The receiver circuit uses the sensitive photodiode and the high precision thermal resistance temperature sensor to form the light intensity and the temperature detection real-time circuit.The signal conditioning of the photoelectric conversion circuit is analyzed and designed,and the simulation experiment is carried out.Finally we achieve the goal of high precision signal acquisition and transmission.The system automation and measurement accuracy are improved.In the last part of the paper,we construct the system principle prototype and make systematic test in the Shanxi Normal University Chemistry Laboratory.Under the 10-50?,we choose potassium KCI-H2 O system as a standard system and make a reliability test for the experimental device.Result shows that the output of the semiconductor laser light power is stable,and the solubility error values of potassium chloride in water is ±0.005 kg and in good agreement with the literature value.The system can overcome the shortcomings of traditional methods and greatly improves the accuracy and efficiency of solubility test which can meet the needs of different industries.