Original research articleA robust optical fiber sensor for the detection of petrol adulteration

An intrinsic intensity modulated no core fiber sensor (NCFS) is presented in this paper for rapid detection of adulteration in petrol with kerosene. The sensing principle is based on the phenomenon of absorption of evanescent waves. The sensing head of NCFS is fabricated by stubbing a small section of no core fiber (NCF) between two multi-mode fibers (MMF). A high sensitivity 390 nW/% and 110 nW/% are obtained by the proposed sensor for low and high level of adulteration. The intensity variation and confinement loss with different concentrations of the kerosene in petrol are then verified theoretically by using finite element method. It is found that the theoretical results agree very well with experimental results. The proposed sensor exhibits fast response time and good repeatability in addition to its high sensitivity. The sensor can be useful in industries and automotive companies due to its small size, easy to fabricate, safe with inflammable fuels and required small amount for detection.