An Optical Sensor for Selective Detection of 2-Furaldehyde in Transformers Oil under Flow

In this work an investigation on the behavior of an optical sensor for the detection of 2-Furaldehyde (2-F AL) in a mineral oil under flow is reported, to pave the way toward a next on-line application of the sensor in oil insulated transformers. The sensor is based on a surface plasmon resonance platform achieved in a plastic optical fibre, which is coupled to a synthetic receptor. This sensor has been previously proposed by the authors as a low cost, highly selective and sensitive optical sensors for the detection in mineral oil of degradation markers of oil-insulated transformers and it has been tested in a drop of oil. Here the study has been extended to the detection of 2-FAL under oil flow. It has been found that the optical response is the same under oil flow and in oil drop. In particular, the affinity constant of the synthetic receptor is the same, confirming the repeatability of the sensor response and the absence of degradation process of the synthetic receptor over time, even under oil flow.