Plastic Optical Fibre Sensing of Fuel Leakage in Soil

Masayuki Morisawa,Shinzo Muto

doi:10.1155/2012/247851

Abstract

A basic operation of the very simple optical sensing system of fuel leakage in uniform sandy and clayey soils, which is consisting of a plastic optical fibre (POF) transmission line, the POF-type sensor heads, and a single LED photodiode pair, has been studied theoretically and experimentally. Its sensing principle is based on the POF structure change in the sensor head caused by fuels such as petrol. A scale-downed model prepared in the experimental room showed a possibility of optical detection of fuel leakage points in uniform soil. As this system operates without receiving the influence of water containing in fuels and soils, its application to fuel leak monitor around a filling station and oil tank can be expected.

Highlights

At present, various fuels such as petrol, kerosene, and light oil are used in many fields to make our life comfortable
A very simple system consisting of the plastic optical fibre (POF) transmission line and the POF-type sensor head showed a possibility on optical detection of the fuel leakage point in uniform soil around a filling station and/or oil tank
The very simple POF-type optical sensing system of fuel leakage in uniform soils, which is based on the POF structure change in the sensor head produced by a swell phenomenon in the cladding layer, has been studied using a scale-downed model

Summary

Introduction

Various fuels such as petrol, kerosene, and light oil are used in many fields to make our life comfortable. Considering the practical application around a filling station and oil tank, more simple and low-cost ones are desired. From this background, we made an attempt to develop a very simple and low-cost optical sensing system to detect leakage of fuel in soil. According to the preliminary study, certain kinds of polymer such as polyisoprene (PIP) cause swelling by attachment of fuel molecules and change its refractive index remarkably [6]. Based on this phenomenon, the POF-type sensor head to detect petrol was fabricated and tested. This paper reports on its basic property towards development of the practical system

Application Model and Its Operation Principle

10 Fuel sample on

Detection Method of Fuel Leakage Point

Leakage point B

Conclusions