Development Of High Speed And High Precision Near-infrared Data Acquisition System

Near Infrared Spectrometer(NIR) which were researched and applicated in many countries,developed rapidly and has widely application prospects.In recent years,it has got progess in our country but still has big gaps with the international level in system precision and need to be improved.The hardware design principle,design method and its performance test results of the precision of near infrared measuring system are described synthetically.According to the principle of near infrared spectrum,the new light road system and circuit system were designed, and the filter of high spectrometer near infrared was built.In comparison with many experiments of scheme,a low noise amplifier chipset and a high performance 24-bit analog-to-digital converters(ADCs) chipset were introduced.C8051F was used which has the compact peripheral circuit singleship design the control and data-acquisition circuit.A data-acquisition system based on C8051F was presented.The complete measurement system was designed.The datas will be sent to the host computer after it's been processed.Then the data-acquisition system and the data-process software were designed.To further improve the precision of the system,software way was used to filter the collection of data.The design consideration of lightsource,stray light circuit parameters,the influence of factors.The water experimental results show that when the conversion rate is 3.9 KHz,the measured precision is up to 15 bit,equal 0.3×10^-4,This system were proved to meet the require of the filter-transmittance-type NIRS.