Development Of Microsugar Detecting Instrument Based On STM32F407

There is a huge energy consumption in the sugar refining process, which is divided intojuice extracion, clean, evaporation, sugar boiling and crystallization, honey separation process.Especially the evaporation process, its energy consumption takes a large proportion in theentire process, and is one of the central link in energy saving. Therefore, researchers found“Multi-Effect Evaporation” theory that is successfully applied to evaporation system. Ittransports vapor which contains a great quantity heat from each effect evaporator into the nexteffect as heating stream for reusing. Each effect evaporator also generates a lot of high puritycondensate that have much of heat at the same time. Some condensate is transported intoboilers as feed water for further energy saving. But the micro-sugar in condensate would leadto some unfavorable influence for boilers. On the basis of the acutal technology, the sugarfactories have made micorsugar standard of feed water correspondently, for example25ppm,50ppm. So it is necessary to test the condensate before going into boilers. Therefore, thispaper designed and developped a set of instument that is based on the STM32F407microprocessor to test micorsugar.Based on the reaction of micro sugar with molybdate under acidic condition to form ablue complex called molybdenum blue, this detection system tested the variation ofphotoelectric signal using photometry. Designing a continueing reaction platform; theperistaltic pumps are controlled by three motor controllers, transport the materials and pushthe reaction move. The signals are generated by a suitbale laser tranmitter and photoelectricsensor, then process by two stage amplification and input into A/D after limiting protectioncirtuit. Then the signals are collected at a sampling frequency of2.4Msps, and then processedby a improved digital filter algorithm. The effective sampling values are used to calculate thetransmittance, absorbency and concentration of micor-sugar. STM32F407micorprocessor hasthe characteristic of high performance, low power and so on. Disigning a5d key-press, LCDDisplay Screen, serial and CAN communication in order to detect system more humanization.Then several performances of software and hareware will be tested to guarante the regularoperation in the system. According to the complete machine testing experiments, tests experiments were carriedout on the photometric repeatability experiment and photometric precision ecperiment. Andthese turn out that the system has a high reliability. From the experiment of curve fitting, wefound that the regression value of concentration of micro-sugar(0~100ppm) on resultant’sabsorbance is quadratic polynomial. It can be used to calculate the micro-sugar concentrationbetween0and100ppm.