Research For The Lower Computer Of ICP Single-Channel Scanning Spectrometer

With the rapid development of spectroscopy technology, people's demand for atomic emission spectrometer is increasing. Wherein, based on grating principle inductively coupled plasma(Inductively Coupled Plasm, ICP) atomic emission single-channel scanning spectrometer draw widely attention for qualitative analysis and selecting lines arbitrarily. But the technology has been monopolized by some countries for a long time,plusing price and to maintainance being expensive.In order to facilitate the domestic users,it is urgent to carry out research work in this area.This paper designs single-channel scanning ICP spectrometer lower computer hardware and firmware, and develops the equipment. In the study, we also establish the spectral interference analysis model and calculate the wavelength localization coefficients. Details are as follows:1)A design module for spectral signal's acquisition and processing. This module designs a low noise single operational amplifier, a gain joint controlled by high voltage negative and gain value and a a volt-frequency optical detection system conversion chip configuration to achieve the optical signal conversion, amplification and acquisition; This module designs the pneumatic control system which includes mass flow controller and the analog to digital conversion chip, achieving a precise control of the plasma gas, carrier gas and auxiliary gas. This system ensures stable operation of the plasma for its fast response and flow stability. This module also designs a control and communication systems constituted by the FPGA control chip and communications network interface chip which achieves control of the entire system and is stable, reliable, strong anti-interference ability.2) The firmware design of the overall architecture of the next crew base on FPGA. PC communication module is designed to achieve the related control and data transmission.wavelength motor control module is designed to achieve the Homing pole, peak search,locate measurement and automatic attenuation function; AD, DA drive module is designed to achieve a high voltage, gain settings and auxiliary gas, plasma gas, carrier gas and other equipment status monitoring. The design of Firmware part provide a guaranteefor the accuracy and stability of the spectrometer measurements.3) The established Spectral interferences analysis model is and the calculated wavelength positioning coefficients are improve the spectral performance and wavelength precisionpositioning of the spectrometer further.4) Spectrometer performance testing part is responsible for the testing of the spectrometer hardware, software and machine performance. The results show that the spectrometer have reached the national spectrometer designation criteria. Some measurement results of the elements are even far beyond national standards with the obvious advantage of fast analytical speed, multi-element analysis simultaneously, low detection limit, wide linear dynamic range and low cost analysis.The research results have a supporting influence for promoting the independent development of single-channel scanning ICP spectrometer technology.