SIST EN ISO 15091:2020 PDF

Overview

EN ISO 15091:2020 (Paints and varnishes - Determination of electrical conductivity and resistance, ISO 15091:2019) specifies a laboratory method to measure the electrical conductivity, electrical resistance and to derive resistivity of coating materials. The standard covers both water-borne (including electrodeposition) and solvent-borne paints and varnishes and applies to products with conductivity < 5 µS/cm (resistivity > 200 kΩ·cm). It is intended to assess how coating formulations behave in the presence of electric fields - a key factor for electrodeposition and electrostatic processing.

Key Topics and Requirements

• Scope and applicability
  • Conductivity measurement typically for water-borne and electrodeposition coatings.
  • Resistance measurement typically for solvent-borne coatings.
  • Applicable range: conductivity less than 5 µS/cm (resistivity greater than 200 kΩ·cm).
• Measurement principles
  • Determination by voltage/current measurement or comparison via a reference (e.g., bridge circuits/Wheatstone bridge).
  • Use of alternating current (AC) is recommended to avoid electrolysis and polarization; frequency should be kept as low as practical to reduce cell reactance.
  • Two-electrode and four-electrode configurations are described.
• Apparatus and calibration
  • Instruments must be calibrated (see Annex A). Measuring cells require a known cell constant and electrodes made from inert, easy‑to‑clean materials (e.g., stainless steel, platinum, graphite, titanium).
  • Ensuring complete immersion and appropriate sample viscosity/conditioning is part of the procedure.
• Test conditions and reporting
  • Defines test conditions, sample preparation and number of determinations.
  • Includes guidance on expression of results, precision and temperature dependence (Annex B).

Practical Applications and Users

• Who uses EN ISO 15091:2020:
  • R&D and formulation chemists developing electrodeposition or electrostatically applied coatings.
  • Quality control laboratories checking batch-to-batch conductivity/resistance.
  • Suppliers of raw materials (additives/solvents) concerned with electrical properties.
  • Coating application engineers ensuring processability in electrostatic or cathodic/anodic deposition.
• Practical benefits:
  • Ensures consistent electrostatic behavior and processability.
  • Helps diagnose formulation issues (e.g., ionic contamination, solvent effects) that affect deposition or finish quality.
  • Supports compliance and comparability across labs by defining measurement method and calibration.

Related Standards

• Normative references cited: ISO 1513, ISO 3696, ISO 4618, ISO 15528 - relevant for sample preparation, water quality, terminology and sampling.

Keywords: EN ISO 15091:2020, electrical conductivity, electrical resistance, resistivity, paints and varnishes, electrodeposition, electrostatic processing, measuring cell, cell constant, conductivity measurement.