用于颗粒物监测仪的小型法拉第杯的优化设计

摘要

设计出一种结构简单、尺寸小,可用于微型超细颗粒物监测仪的法拉第杯.法拉第杯气流采用从敏感电极部分的前端进、后端出方式,内部敏感电极部分为镂空结构,可填充多孔金属材料.对法拉第杯的离子检测模型进行理论分析表明,提高法拉第杯中敏感电极碰撞表面积可有效提高法拉第杯的离子检测效率.经过优化设计的法拉第杯敏感电极内部填充PPI为60的多孔金属材料,比优化前的法拉第杯检测效率提高86%,配合只需放大倍数1012的静电计便可满足对普通室内环境的大气超细颗粒物数浓度的检测.设计的法拉第杯提高了颗粒物所带的电荷的检测效率,可用于大气超细颗粒物数浓度检测.%A simple structure,small size Faraday cup which used for miniature ultrafine particle monitor was designed.Fara-day cup airflow went from the sensitive electrode front,went out from the backend.Internal sensitive electrode was designed with hollow structure to fill the porous metal material.Through the study of the theory of Faraday cup ion detection model analysis,it showed that improving the Faraday cup sensitive electrode collision area can improve the efficiency of Faraday cup ion detection effectively.Optimized design of Faraday cup detection efficiency increased by 86%than before optimization which sensitive elec-trode internal filling PPI is 60 of porous metal materials,with only 1012magnification of the electrometer can satisfy for atmospher-ic ultrafine particles in common indoor environment testing.Faraday cup design in this paper improves the efficiency of the detec-tion of particles with the charge,can be used for atmospheric ultrafine particle number concentration.