Case 830 ยท Public preview
Sequential Grinding Can Expose a Hidden High-Voltage Short Path
An insulated feed-through terminal measured approximately 1.5 ohms from its conductor to the grounded case, with no visible external short path.
Resistance monitoringOptical microscopySequential grindingSEMEDSInsulation-thickness evaluation
What the evidence preview establishes
An overvoltage exceeded the dielectric strength of the PTFE insulation. Internal breakdown carbonized the polymer and vaporized brass from the conductor, forming a conductive bridge to the grounded case.
Why this case matters
For a low-resistance feed-through short with no external path, monitor resistance during serial sectioning. Carbonized polymer, vaporized electrode metal, and directional material loss can distinguish internal overvoltage breakdown from surface contamination.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.