Overview
ISO 19396-1:2017 - "Paints and varnishes - Determination of pH value - Part 1: pH electrodes with glass membrane" specifies a standardized laboratory method to measure the pH of polymer dispersions and coating materials using pH electrodes with a glass membrane. The standard covers required apparatus, electrode types, sampling, calibration, measurement procedure, evaluation, precision and test reporting. It is part of the ISO 19396 series (Part 2 covers ISFET electrodes).
Key topics and technical requirements
- Scope and principle: Laboratory measurement of pH for aqueous paints, varnishes and polymer dispersions using a glass‑membrane potentiometric measuring chain (combination electrode + reference).
- Apparatus: pH meter (reading accuracy 0.01 pH), pH electrode with integrated temperature sensor recommended, buffer solutions, containers, cleaning and storage solutions, stirrers and thermostats.
- pH electrode types: Solid electrolyte, liquid‑electrolyte refillable (annular gap, capillary, protruding ceramic diaphragms) and low‑maintenance designs - guidance provided in Annex A.
- Calibration and performance: Calibration with at least two buffer solutions to determine practical slope and zero point; meter must show pH proportional voltage (mV) and temperature; temperature compensation is required for buffer behavior.
- Procedure and sampling: Defined test conditions, sample preparation and number of determinations to ensure representativeness and reproducibility.
- Evaluation and precision: Includes repeatability and reproducibility considerations based on interlaboratory tests; Annex B describes determination of precision.
- Reporting: Required elements for a complete test report to support traceability and quality control.
Practical applications
- Quality control of coating production (pH stability, batch-to-batch consistency)
- R&D and formulation development for paints, varnishes and polymer dispersions
- Shelf‑life and durability testing where pH affects product performance
- Regulatory and compliance testing where documented, standardized pH methods are required
- Calibration and validation of laboratory equipment and measurement procedures
Who should use this standard
- Paint, varnish and coatings manufacturers (QC and R&D labs)
- Third‑party testing laboratories and certification bodies
- Instrument and electrode manufacturers
- Technical managers responsible for process control and product specification
Related standards
Keywords: ISO 19396-1:2017, pH measurement, paints and varnishes, pH electrodes with glass membrane, polymer dispersions, coating materials, calibration, buffer solutions, pH meter.
Open preview (PDF)Paints and varnishes — Determination of pH value — Part 1: pH electrodes with glass membrane