Design Of Monochromatic Optical Controller In Near-Infrared Reflectance Spectroscopy Instrument

With the development of science and technology, the applications of the Near-Infrared Reflectance Spectroscopy Analysis Instrument (NIRSAI) are getting more and more broad. The measurement, which did not destroy the object, paid more attention. The NIRSAI absorbs the Near-Infrared Reflectance Spectroscopy (NIRS) in some regions by using the bend and flex of chemical bonds between atoms in mineral crystal lattices. According to the Characteristic Absorbing Spectroscopy of certain mineral function regiment in the NIRS region can distinguish different minerals, or different crystal degree in the same mineral in order to check the objects. Using multi-element linear equation, the NIRSAI forecasts the quantity of ingredient in complex samples. It required that the instrument could probe the samples in many kinds of wavelength and continuum spectroscopy; meanwhile, it could check the weak absorbing change of light. So the Spectroscopy Measurement Instrument is needed to be high Signal-to-Noise Ratio and good stability. In order to reach above aim, the instrument must be advanced in technology. The key factor that influencing the stability of NIRSAI's hardware is the Prismatic Optical System of the instrument. According to Prismatic Optical System, modern NIRSAI may be divided into Fixation Wavelength Filter, Raster Display Optical Dispersion, Fast Fourier Transformation, and AOTF(Acoustic Optical Tunable Filter), etc. Nowadays, the Prismatic Optical technology which can be applied is Filter,Scan Raster Display,Fast Fourier Transformation, Diode Array and AOTF etc. As a new technology appeared in 90s of 20th century, experts regard the AOTF as the most development in the NIRSAI. The whole solid-state design of the technology make the NIRSAI adept all sorts of testing condition. The technical Prismatic Optical apparatus of the AOTF (AOTF) adopted double refraction crystal, adjust wavelength of scan by changing radio frequency. The whole instrument has no moveable apparatus, scanning quickly and good stability. It is suitable for analysis on-line. Though it is appeared in 90s of 20th century, many people have achieved a lot of achievement at the same time. But in our country, the applications of the AOTF in prismatic system are still blank. The characteristic of AOTF is small cubage, simple operation, small requires for operation condition. The small cubage is the precondition for the portable instrument. The simple operation isconvenient for the design of instrument. The aim of the dissertation is to study the Monochromatic Optical Controller of portable instrument, which bases on The NIRS. Applying the new advanced prismatic technology, AOTF and DDS, we designed a stable, reliable, portable and convenient Monochromatic Optical Controller, providing effective monochromatic optical source for the NIRSAI. So physical quick convenient NIRS analysis can be realized, meanwhile, the foreign monopolization is broke. It is coming to be true that the quick portable NIRSAI ca be made in China. The main work and the result of this paper are as follows: Chapter 1: NIRS and NIRSAI The concept and the theory of NIRS Analysis instrument are introduced; meanwhile, the aim, significance, content and the important questions to be solved are illustrated. Chapter 2: The design of the Homochromy Optical Controller. The theory and main technical standard of the Homochromy Optical Controller are given. Chapter 3: The key technology of the Homochromy Optical Controller In this Chapter, The following contents are introduced: The application of DDS, the theory and application of AD9852, the theory and application of AOTF, the design of matching circuit and the choice of CPU in the Homochromy Optical Controller. Chapter 4: The software of the Homochromy Optical Controller The main program of the Homochromy Optical Controller, the program of serial communication and the program of DDS are...