ISO 17470:2014 PDF

Overview

ISO 17470:2014 provides guidance for qualitative point analysis by wavelength dispersive X‑ray spectrometry (WDS/WDX) using an electron probe microanalyser (EPMA) or a scanning electron microscope. The standard focuses on identifying which elements are present within a defined micrometric volume (μm3 scale) by analysing WDX spectra, and on documenting the measurement conditions and identification method to avoid inconsistent or erroneous results.

Key topics and technical requirements

• Scope and purpose: Guidance for element identification and investigation of specific elements at micrometric scale using EPMA/WDX.
• Apparatus and instrument performance: Ensure correct electron column alignment, stable beam current, suitable accelerating voltage, calibrated spectrometer crystals and X‑ray counters, and appropriate sample surface preparation.
• Primary beam settings: Select beam energy above excitation energies but low enough to minimize damage, contamination and detector saturation. For very light elements (Be to F), a primary beam energy of 15 keV or less is recommended to reduce absorption effects.
• Spectrometer configuration:
  • Diffraction crystal selection to maximize peak‑to‑background and resolution while minimizing interferences.
  • Scanning speed should give sufficient data points per peak (practically, measured peaks should contain at least five data points).
  • Pulse height analyser discrimination can suppress higher‑order reflections but must be validated with reference materials to avoid loss of signal.
• Spectrum analysis and peak recognition:
  • Use reliable X‑ray line tables or laboratory standards to identify peaks.
  • Evaluate peaks by FWHM and peak height above background. Peaks exceeding background by 2σ or 3σ correspond to approximate confidence levels of 97.7% and 99.9%, respectively.
  • Check for higher‑order reflections, overlapping peaks, absorption/fluorescence effects and possible contamination from sample preparation.
• Reporting: The standard specifies information to include in a test report; Annex A gives an example (stainless steel).

Applications

• Qualitative element identification in microstructures, inclusions, coatings, thin films, ceramics, metals and geological samples.
• Failure analysis, contamination/source tracing, quality control and research where spatially resolved elemental presence at the micrometer scale is required.
• Validating sample preparation and EPMA/WDS operating procedures for laboratories performing microbeam analysis.

Who should use this standard

• Materials scientists, metallurgists, geoscientists, semiconductor and thin‑film engineers
• Electron microscopy and microanalysis laboratory managers and technicians
• Quality assurance personnel and researchers using EPMA/WDS for qualitative point analyses

Related standards

• ISO 14594:2003 - Microbeam analysis - EPMA - Guidelines for determination of experimental parameters for WDS (normative reference cited in ISO 17470:2014).