Overview
EN ISO 16773-1:2016 (ISO 16773-1:2016) establishes the standardized terms and definitions for applying electrochemical impedance spectroscopy (EIS) to coated and uncoated metallic specimens. Published by ISO and adopted by CEN as a European Standard, this part of the ISO 16773 series harmonizes vocabulary, units and symbols used in EIS testing, data presentation and interpretation across coatings and corrosion testing contexts.
Key topics
This part is a terminology reference and therefore focuses on clear definitions rather than test procedures. Important entries and concepts include:
- Electrochemical impedance spectroscopy (EIS) - definition of the technique and its purpose.
- Signal descriptors: peak-to-peak amplitude, rms amplitude.
- Graphical representations: Bode plot (|Z| and phase vs frequency).
- Interface quantities: charge transfer resistance (Rct), double-layer capacitance (Cdl).
- Coating-specific terms: coating capacitance (Cc), coating resistance (Rc), coating (layer vs process).
- Measurement apparatus and environment: electrochemical cell, working / counter / reference electrodes, galvanostat, Faraday cage, ground types.
- Modeling and quality: equivalent circuit, dummy cell, error estimate, electromagnetic noise.
- Units and typical magnitudes for specific elements (e.g., capacitances in micro-/nano‑farads, resistances in ohms/gigaohms) are specified where applicable.
Practical applications
Although Part 1 only defines terminology, it is essential for consistent application of EIS across industries. Typical uses:
- Standardized reporting and communication of EIS results in coatings testing, corrosion studies, research and quality control.
- Reference vocabulary for writing or interpreting test procedures in ISO 16773-2 (data collection), 16773-3 (data processing/analysis) and 16773-4 (spectra examples).
- Supporting calibration and validation of instrumentation (dummy cell concepts) for potentiostats/galvanostats and EIS analyzers.
- Enabling regulatory, procurement and contract specifications where consistent terminology and units are required.
Who uses this standard
- Coatings scientists and formulators, corrosion engineers, materials researchers
- Test laboratory managers and technicians performing EIS measurements
- Instrument manufacturers and calibration labs
- Quality assurance, specification writers, and standards committees
Related standards
- ISO 16773 (series): Part 2 - Collection of data; Part 3 - Data processing and analysis; Part 4 - Examples of spectra
- ISO/TR 16208 - Background principles and practical guidance for EIS on corrosion
Keywords: electrochemical impedance spectroscopy, EIS, ISO 16773-1, coatings, coated metallic specimens, uncoated specimens, terms and definitions, Bode plot, equivalent circuit, dummy cell, corrosion testing.