High-Precision Induction Coil Sensor With High Magnetic Field Homogeneity for Online Debris Monitoring

Considering existing studies on debris sensors neglect the important precision metric, this article proposes a high-flow debris sensor featuring an integrated structure of multiple excitation coils, demonstrating excellent sensitivity and precision. By combining the magnetic field distribution model with the magnetization mechanism of debris, a method was derived to calculate the induced voltage. The optimal structural design parameters of the excitation coil were obtained through simulation to enhance the magnetic field homogeneity, and the impact of parameters such as the number of turns and the configuration of coils on structural optimization was analyzed. The detection signal which was acquired using techniques such as coherent demodulation and filtering amplification validated the sensor’s sensitivity and precision. The results of the experiment indicated that iron debris with a diameter of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$143~\mu $ </tex-math></inline-formula>m and copper debris with a diameter of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$667~\mu $ </tex-math></inline-formula>m can be identified in a pipe radius of 6 mm, with a result error of less than 8.4%, and the precision is at least 59.6% higher compared than other debris sensors. The design concept of this sensor can be applied to various types of debris sensors and other online detection equipment for great performance improvement.