AlloySnap: A Contact Eddy-Current Alloy Wand for Nonferrous Scrap Yards

A cheap, one-button handheld wand that identifies the common nonferrous scrap alloy families (copper, brass, aluminum, stainless, zinc, lead) on contact using an eddy-current antenna whose geometry and drive parameters are set by modeling — no X-ray tube, no radiation-safety overhead, no consumables.