The basic principle of eddy current testing is introduced and the coil impedance responses due to the variations of the probe coillift-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
Under the action of variation magnetic field, the permanent magnet moving-coil drives the plunger pump to move up and down and lift oil up to ground.