The basic principle of eddy current testing is introduced and the coilimpedance responses due to the variations of the probe coil lift-off are analyzed and studied.
简要介绍了涡流检测的基本原理和涡流探头的特性； 分析和研究了涡流检测探头提离变化对阻抗的影响；
2
The dotted line connecting the tops of the two capacitors represents the low coilimpedance to ac signals.
两个电容顶部的虚线表示切换交流信号时的线圈阻抗。
3
The emitting coil and capacitance are connected in parallel and form a resonant amplitude-modulation circuit, which converts the impedance into output voltage.