涡流检测 ECT

           EDDY CURRENT TESTING   ECT

■检测原理:当载有交变电流的试验线圈靠近导体试件时，由于线圈产生的交变磁场的作用会在导体中感生出涡流。涡流的大小、相位和流动形式受到试件性能及有无缺陷的影响，而涡流的反作用磁场又使线圈阻抗发生变化。利用这种电磁感应现象来判断材料性能和缺陷的方法。

Principle: When the test coil carrying the alternating current isclose to the conductor, the eddy current is induced in theconductor due to the action of the alternating magnetic fieldgenerated by the coil.The size, phase and flow pattern of theeddy current are affected by the performance of the test pieceand the presence or absence of defects, and the reactionmagnetic field of the eddy current causes the impedance ofthe coil to change.Use this phenomenon of electromagneticinduction to judge material properties and defects.

■适用的检测对象:导电材料及其制品。Application: conductive materials and their products.

■优点:采用非接触式检测，检测速度很快;:表面和近表面缺陷检出灵敏度高;能在高温状态下进行检测。Advantages:Non-contact detection,fast detection speedHigh sensitivity for surface and near surface defect detection;ET can be conducted at high temperature.