The Study Of Fluorescence Spectrometer Used In Measuring Algae On The Spot

In recent years, the frequent occurrences of the red tide have influenced the environmentof ocean greatly, and attracted widespread attention. Making qualitative and quantitativeanalysis for the algae in the ocean can estimate community structure and distribute status ofecosystem in some sea area, and then we can monitor and forecast red tide. Fluorescencemethod is an important method that is used to identify algae's class and consistenceanalyzing. Development of fluorescence spectrometer used in measuring algae on the spothas a research and practical significance.In this paper, a method on how to design a kind of fluorescence spectrometer used inmeasuring algae on spot is introduced. And according to this method, a prototype instrumentis developed successfully. This instrument is divided into upper part and lower part whendesigning. The lower part is made up of a circuit based on MCS51 and optical system, whichachieves several functions such as choosing excitation light source, controlling grating's scan,spectral data collection, communicating with the upper part. When designing the opticalsystem, thirteen LEDs are selected as excitation light source, and the Czerny-Turner typemonochrome is used to make the light dispersive. Both of the measures can help reducing theinstrument's volume. And using the PMT as light detector can enhance the sensitivity of theinstrument. The upper part is a personal computer in this prototype instrument, and it hassoftware developed by VB language, with this software it achieves many functions, such ascontrolling lower part's work by serial port, display and save the spectrum. Experimentsshow that this instrument has satisfied all demands required.In order to satisfy the demands of outer-filed use, an embedded system using ARMprocessor is developed to take the place of personal computer. This embedded system basingonμC/OS-II real-time operation system and S3C44B0X processor has realized the graphicuser interface (GUI), FAT file system and USB communication functions.The following works have been finished in this paper:1) Found an optical system includes high-brightness LEDs as light source,Czerny-Turner type monochrome instrument and PMT, and found a control circuitbased on MCS51 to finish spectral data collection.2) Develop software for computer with VB language to achieve spectral display,spectral data storage and other functions.3) Designed an embedded system includingμC/OS-II RTOS andμC/GUI. Haveanalyzed the structure ofμC /GUI and how to program the driver, and ported it tothe S3C44B0X's LCD controller. 4) Achieved the function interface to access FAT16 file system, so it can store the massdata measured in the spot.5) Using the USB controller chip PDIUSBD12, communication function between theembedded system and personal computer is achieved. Together with FAT16 filesystem, the data flash memory is developed to be a U disk, which makes the datatransmission between the instrument and personal computer very convenient.