Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Sensors (Basel). 2013 Aug 29;13(9):11476-89. doi: 10.3390/s130911476.
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.
我们提出并构建了一种基于光纤布拉格光栅（FBG）附小磁铁的简单非接触力传感器。该传感器可测量磁铁与放置在距传感器几毫米内的任何铁磁材料之间的力。通过将传感器保持在恒定的距离，由于腐蚀导致的材料损失会增加磁铁和腐蚀表面之间的距离，从而减小磁力。这将减小光纤中的应变，从而改变反射布拉格波长。所使用的光纤的测量位移为每牛顿 1.36nm。为了特定的传感器距离和特定的腐蚀坑深度，我们开发了模型来优化磁铁的几何形状。该传感器能够检测燃料储罐底部深度在亚毫米范围内的腐蚀坑。
