Differential Eddy Current Probe
The differential eddy current probe consists of two coils connected in opposition. It detects local inhomogeneities and cracks in the weld.
Physical-Chemical Mechanism of Action
The differential eddy current probe uses two coils connected in opposition. A current flow through one coil generates a magnetic field that is measured by the other coil. Local inhomogeneities or cracks change the magnetic field and are thus detected.
Metallurgical Relevance & Risks in Welding
The differential eddy current probe is especially sensitive to local strength differences and cracks in the weld. It can help detect brittle areas or hot cracks early before they become larger problems.
Workshop Practice & Instructions
Use the differential eddy current probe in the weld zone to check for local inhomogeneities and cracks. The coils should be positioned so that they cover the entire weld area. A positive indication means strong reinforcement or a crack. Pay attention to correct calibration of the probe and perform regular tests.