EIS corpus — normalized engine-ready spectra (v1)

Normalized, engine-ready electrochemical impedance spectroscopy corpus: 142,691 spectra in 48 banks and 7 sectors. Every bank contains the exact tidy spectra used by the engine (id,label,frequency_hz,z_re,z_im), the published circuit labels where available, optional parameters/metadata, and a manifest with the source DOI/URL, adapter and transformation notes. The raw source archives are not redistributed. The record also includes a format guide, a provenance table, licence notes and a combined CHECKSUMS.txt; the archive includes validation tools. The selection, arrangement, normalization, manifests and checksums are CC BY 4.0; the normalized spectra are derived from the sources and each source retains its own licence.