A Noncontact Force Sensor Based on a Fiber Bragg Grating and Its Application for Corrosion Measurement

Sensors

Clara J. Pacheco¹ 

[1] Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, Rio de Janeiro, RJ 22451-900, Brazil; E-Mail

关键词: fiber Bragg grating;    magnetic force sensor;    photonic force sensor;    internal corrosion;   

DOI  :  10.3390/s130911476

来源: mdpi

【 摘 要 】

A simple noncontact force sensor based on an optical fiber Bragg grating attached to a small magnet has been proposed and built. The sensor measures the force between the magnet and any ferromagnetic material placed within a few millimeters of the sensor. Maintaining the sensor at a constant standoff distance, material loss due to corrosion increases the distance between the magnet and the corroded surface, which decreases the magnetic force. This will decrease the strain in the optical fiber shifting the reflected Bragg wavelength. The measured shift for the optical fiber used was 1.36 nm per Newton. Models were developed to optimize the magnet geometry for a specific sensor standoff distance and for particular corrosion pit depths. The sensor was able to detect corrosion pits on a fuel storage tank bottom with depths in the sub-millimeter range.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.