ISO 19396-1:2017

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

• ISO 19396-2 (pH measurement using ISFET electrodes)
• Normative references used in the document: ISO 1513, ISO 4618, ISO 15528, and ISO 80000‑9 (quantities and units for physical chemistry).

Keywords: ISO 19396-1:2017, pH measurement, paints and varnishes, pH electrodes with glass membrane, polymer dispersions, coating materials, calibration, buffer solutions, pH meter.