Liquid level gauge based in plastic optical ﬁber
The accurate liquid level measurement in large indus- trial containers is a difﬁcult task, especially for highly ﬂam- mable environments, where the use of electronic sensors can be problematical, or even banned by law, due to the risk of electric sparkle.
Nowadays, the petroleum and other petrochemical industries have speciﬁc and tight requirements related with the production quantiﬁcation. Such as the require- ment to quantify the production volume, by inferring the liquid level in the container (typically with some meters height). This requirement is not only an individual compa- ny requirement, to control the company production efﬁ- ciency and gains, but also a legal imposition to estimate ﬁscal taxes . Usually, the liquid level in the container is measured by traditional technologies, such as differen-tial pressure level meters, radar, magnetostrictive, or mag- netic ﬂoat technologies [2,3]. However, some limitation may apply, since such methods are electronic and the sens- ing system is often exposed to combustible liquids or accu- mulated ﬂammable vaporous environments.