2017 年 25 巻 2 号 p. 212-217
Eddy-current rail displacement sensors are used for confirming rail displacement. However, collision with gravel and snow due to the short distance between rail head surface and sensor causes failures or malfunctions. Therefore, it is necessary to increase the distance from the rail head surface to the eddy-current rail displacement sensor. So with high quality factor coil in order to realize a conventional double lift off. Electric field generated from the coil by the magnetic field is amplified to amplify. Susceptible to disturbances such as a high dielectric constant of water by the electric field is generated. Therefore, it is necessary to suppress the electric field is increased. It suppressed electric field by using an electric-field shielding. In this paper, it allowed the detection of rail displacement while suppressing the electric field by implementing an electric field shield.