A Polyimide Diaphragm-Based Extrinsic Optical Fiber Fabry-Perot Acoustic Sensor for the Detection of High-Frequency Ultrasonic Signals in Transformer Oil

Abstract

This article shows an extrinsic optical fiber Fabry-Perot (F-P) acoustic sensor based on a polyimide diaphragm whose effective vibration area and thickness respectively are approximate 4.906 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 8.5 μm for the high-quality detection of high-frequency ultrasonic signals in transformer oil. Directional test indicates this proposed sensor is an omnidirectional sensor. And experimental results of the detection for high-frequency ultrasonic signals in transformer oil indicate this proposed sensor has a flat frequency response, which demonstrates this proposed sensor can achieve the high-quality detection for high-frequency ultrasonic signals in transformer oil. Therefore, this proposed sensor also has excellent potential for the detection of partial discharges occurring in transformer oil in any direction.