基于长周期光纤光栅的成品油中乙醇含量检测

Ethanol content detection in oil by long period fiber grating

提出采用长周期光纤光栅(LPFG)测量乙醇汽油与乙醇柴油的研究。利用耦合模理论分析了LPFG的折射率敏感特性,得到LPFG谐振波长漂移量与外界环境折射率的关系,并将其用于乙醇汽油和乙醇柴油中乙醇含量的检测,得到乙醇汽油与乙醇柴油中乙醇含量与LPFG谐振波长漂移量的关系。实验结果表明,乙醇汽油中,乙醇含量每改变1%,谐振波长平均漂移量为0.047 7nm;而乙醇柴油溶液中,乙醇含量每改变1%,谐振波长平均漂移量为1.154 4nm。实验测量与理论仿真的结果基本一致,验证了LPFG用于乙醇汽油和乙醇柴油检测的可行性。

A long period fiber grating is used to detect ethanol concentration of ethanol gasoline and ethanol diesel experimentally.First of all,the long period fiber grating refractive index sensitivity is analyzed by couple-model theory,and the relationship between the long period fiber grating resonance wavelength shift and environmental refractive index is obtained by theory.Then it is used to detect ethanol content in ethanol gasoline and ethanol diesel,and at last the relationship between the ethanol concentration of ethanol gasoline and ethanol diesel and long period fiber grating resonance wavelength shift is obtained by experiment.The experimental results indicate that as the ethanol concentration change every 1%in ethanol gasoline,the long period fiber grating average resonance wavelength shift is 0.0477nm,and as the ethanol concentration changes every 1%in the ethanol diesel,the long period fiber grating′average resonance wavelength shift is 1.1544nm.The experimental results we got can fit the theoretical simulation results very well.So the long period fiber grating could be used to detect ethanol concentration of ethanol gasoline and ethanol diesel.