双通道差分式阻抗谱检测技术及仪器研究  

Research on Two-channel and Differential Impedance Spectroscopy Measurement Technology and Instrument

作　　者：龚应忠[1] 管亮[1] 冯新泸[1] 王立光[1] 刘汉臣[2] 朱立业[2] 

机构地区：[1]后勤工程学院油料应用与管理工程系,重庆401311 [2]成都军区联勤部油料监督处,成都610041

出　　处：《分析化学》2016年第1期160-166,共7页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金青年基金(No.21205136);重庆市应用基础与前沿研究(一般)项目(No.cstc2014jcyjA 0592);重庆市研究生科研创新项目(No.CYB14101)资助~~

摘　　要：阻抗谱检测的目的在于获取不同物质之间微弱的介电差异信息或同一物质的介电变化信息,并据此对其组成、结构及其变化特征进行分析。常规单通道的阻抗谱检测技术对于物质间的差异和变化信息检测易受传感器和样品体系等基底信号的影响。本研究提出了一种基于AD5933阻抗转换芯片简化阻抗测量的双通道差分式阻抗谱检测技术,并研制了检测仪器,在1-91 kHz频率范围内,对比分析了基底信号分别为200,400和1000 mV,响应信号增加量0-100 mV时双通道差分和单通道检测的灵敏度,并考察了在激励峰峰值为18 V的条件下汽油、柴油、喷气燃料及润滑油共7个样品在单通道,以空气及喷气燃料为参比的双通道差分检测的灵敏度差异。结果表明,单通道检测受基底信号影响较大,随基底信号增加,检测灵敏度降低;双通道差分式检测技术的灵敏度为单通道检测的1-2个数量级,且不受基底信号影响;以喷气燃料为参比的差分检测灵敏度分别是以空气为参比的差分检测及单通道检测的5-10倍及9-12倍,证实了通过合理选择参比样品,双通道差分检测能够极大地提高阻抗检测灵敏度。Dielectric difference analysis is important for impedance spectroscopy,which is the basis of dielectric materials composition,structure and performance characteristics analysis.As for normal single channel impedance spectroscopy measurement technique,substrate signals resulting from sensor substrate and so on will weaken the dielectric difference dramatically.In this work,a new impedance spectroscopic technique has been proposed,which is characterized by two-channel and differential detection methods and based on AD5933 impedance converter chip.In the frequency range of 1-91 kHz,experiments have been performed with the excitation signal differences from 0 mV to 100 mV under the substrate signal of 200,400 and 1000 mV for new two-channel and differential and normal single channel impedance spectroscopic methods.Seven oil samples including gasoline,diesel fuel,jet fuel and lubricating oils have also been tested by the methods of single channel detection,differential detection with the references of air and jet fuel under the excitation voltage of 18 VPP.The results showed that the impedance response sensitivity of two-channel and differential detection was 1-2 orders of magnitude of the normal single channel detection and free from the influence of substrate signal.For the oil samples,the impedance response sensitivity of differential detection with reference by jet fuel was 5-10 times of differential detection reference by air and 9-12 times of single channel detection,respectively,which proved that the differential detection could improve impedance detection sensitivity and eliminate the effect of substrate signal significantly.

关 键 词：阻抗谱 差分 阻抗转换芯片AD5933 燃料油 

分 类 号：O657.1[理学—分析化学]