Case 2868 ยท Public preview
Rhodium-Plating Nodules Can Concentrate Reed-Switch Contact and Arc Damage
Several reed switches developed elevated contact resistance ranging from hundreds of milliohms to more than one kilohm, while a low-resistance reference measured 44 milliohms.
Contact-resistance comparisonOptical microscopyControlled dissectionSEMEDS
What the evidence preview establishes
Nodular rhodium plating created high points that confined electrical contact to a small fraction of the nominal surface. Repeated closure and arcing at those points produced localized damage, carbon-bearing deposits, and oxidation consistent with increasing contact resistance.
Why this case matters
Contact plating should be evaluated as a surface topography, not only as a composition. When current is confined to nodular high points, correlate resistance with flattened contact regions, arc morphology, and paired damaged-to-undisturbed spectra before assigning the failure to random debris.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, 6 interpreted figures, alternative explanations, limitations, and practical application guidance.