In recent years Near Infrared Spectrum (NIR) is one of the rapid development High-tech analysis and testing technology, which is organic integrated with spectrum measurement technology, computer technology, chemistry technology and the basis of measurement technology. This paper made the research and design based on photoelectric signal acquisition system ,for its A/D conversion, data acquisition and the communication with PC . Photoelectric signal acquisition system is completed with signal amplification, analog-digital conversion, which collected the analog signals and changed it so the computer can read it; then sent the data to the MCU for processing, finally communicating with the computer and show the results . Enlarge circuit which using op07, conversion circuit which using ADC0809, MCU which using AT89C51, communication circuit which using MAX232 and RS232. This circuit is a reasonable and reliable program, is designed simply, cost-effective and it improves the stability and accuracy of the circuit , so it has a certain practical value.
Keywords:Signal acquisition、mcu、A/D conversion