Potential Drop Crack Depth Measurement
Potential probe crack edge measurement is an electrical test where the potential difference across a crack is measured to determine crack depth. It is based on the narrowing of the current flow cross-section.
Physico-chemical mechanism of action
Potential drop crack tip measurement measures the potential difference across a crack in an electric field. With applied DC or AC current, the current flow cross-section narrows at the crack tip, leading to an increased voltage. This voltage change is measured and can be used to calculate the crack depth.
Metallurgical relevance & risks in welding
This measurement is especially important in the shop because it can check the quality of weld cracks. A deep or hidden crack can severely affect the material and lead to hot cracking or stress corrosion cracking. Accurate measurement can determine whether a weld is safe or if repairs are needed.
Workshop practice & instructions
To perform potential drop crack tip measurement, an electric field is applied across the material and the potential difference at the crack tip is measured. The measurement should be done in a quiet environment and without external influences. For accurate results, it is important that the current flow is stable and the measurement is performed correctly. If results are unclear or missing, further testing or repairs should be instructed.