GTET-02 Cylinder Liner Eddy Current Testing Machine Introduction 1. Test object: inner diameter and an outer diameter of the cylinder liner 2. Standard defective parts: a flat bottom hole with a depth of 0.5 mm and a diameter of 0.5 mm extending from the surface of the workpiece to the metal. 4.The rate of missed standard defect is 0%; the rate of false positives (only misidentified products are judged as non-conforming products) ≤1%. Detection method Eddy current testing is to connect the conductor to the coil with alternating current. The alternating magnetic field is established by the coil. The alternating magnetic field passes through the conductor and electromagnetic induction is applied to establish an eddy current in the conductor. The eddy currents in the conductor also generate their own magnetic field, and the action of the eddy current magnetic field changes the strength of the original magnetic field, which in turn causes a change in the coil voltage and impedance.