Eddy Current Testing Machine Makes Inspection Automation Easier and More Convenient

Eddy current flaw detector and inspection automation

Eddy current flaw detector is a non-destructive testing technology which uses the principle that eddy currents generated by an alternating electromagnetic coil on the surface of a metal component will change when encountering defects to detect the defects of the component.

Utilizing the electromagnetic induction principle, the excited coil generates eddy current in the conductive component, and the change of eddy current is determined by the detection coil to obtain information about the component defects.

Eddy current flaw detector is a non-destructive testing technology which generates eddy currents on the surface of metal components using alternating electromagnetic coils. It is suitable for detecting defects in conductive materials, including ferromagnetic and non-ferromagnetic metal components.

Because the eddy current flaw detector does not require the coil to be in close contact with the component during detection, nor does it require a coupling agent to be filled between the coil and the component, it is easy to achieve inspection automation. However, eddy current flaw detector is only suitable for conductive materials. The point-type cable flaw detector is not convenient for detecting components with complex shapes. In thermal power plants, it is mainly used to detect condenser tubes, turbine blades, the center hole of the turbine rotor, and welds.

Advantages of the eddy current flaw detector

The interface of the eddy current flaw detector is relatively good.
The sensitivity of the eddy current flaw detector for small cracks and other defects is high.
The eddy current flaw detector can quickly detect surface and near-surface defects, with high sensitivity.
The inspection result of the eddy current flaw detector is immediate.
The test probe of the eddy current flaw detector does not need to contact the object being tested.
The eddy current flaw detector can inspect conductors with complex shapes and sizes.
The eddy current flaw detector requires very little preparation.

Eddy current flaw detector mainly consists of a detection instrument, coils (probes), marking device, encoder, etc. The probes are divided into through-type, point-type, rotary-type, interpolation-type, etc.

Through-type probes are mainly suitable for tubular materials. The feature is that for long longitudinal injuries, only the signals at the head and tail can be detected, and the middle cannot be detected.

Point-type probes are mainly used for detecting surface injuries, such as weld injuries, and can also be used to measure the thickness of plates or coatings. Rotary-type probes are suitable for tubular materials and can detect long longitudinal injuries. Interpolation-type probes are suitable for internal wall testing of pipes.