Design Of Liquid Chromatography Detection System For Industrial Computer

With the continuous development of economy and the rapid increase of people's living standard,in the medical,chemical,food safety,and other related fields,the needing of testing material cormposition and its content is increasing.On the other hand,liquid chromatography in our country is still in low efficiency and at high cost,and the detection of certain samples needs to be imported from abroad.In view of the above,using some common circuit development board in the market,based on microelectronics and computer technology,we design a dual channel,multiple wavelength and high efficiency liquid chromatography detection system.This article first elaborated working principle of the liquid chromatography detection in detail and its research situations both at home and abroad.Then is describes the performance and work principle of the ultraviolet-visible detector.And with the combination of industrial control and embedded technology,it developed a complete set of liquid chromatography detection system using the Windows system.This test system consists of the lower part machine and the industrial control machine.The lower part machine is driven by the STM32 processor,which drives multiple modules.The control machine is programmed with Qt to complete the control and feedback interface.The hardware part of the system is designed to include:the design of light source power supply module,which includes deuterium lamp fader circuit design and high precision constant current source circuit design;The design of wavelength positioning module,which is to complete the rotation of STM32 control optical grating through the working principle the of wavelength scanning and stepper motor and its drive;The design of signal amplification module,which detects amplifier AD515AL,logarithmic amplifier LOG102 and software programmable amplifier AD526 using a weak current,connects them correctly and forms the design of the external circuit to complete the signal amplification;The design of A/D conversion module which is not the use of a special conversion chip,but the use of U/F converter and a filter circuit to complete the connection;The design of LCD display module which is to complete the wavelength and detection data display in the LCD;The design of serial communication module,using MAX232 conversion chip to achieve TTL and RS232 level conversion.For the system part of the software design includes:the completion of wavelength positioning and A/D conversion code preparation work;create the underlying API function dynamic link library to facilitate the IPC at any time call;anti-control interface design,which completed the interface layout,dynamic link Library input,serial communication,drawing module addition and dual-threaded design work;quantitative algorithm design,through an integral algorithm to calculate the peak area of the chromatogram,resulting in the detection of sample composition.The test shows that the system is stable,high detection efficiency,can be used for large quantities of sample testing.All aspects of the indicators have reached the desired goal.