Overview - ISO 19396-2:2017 (pH electrodes with ISFET technology)
ISO 19396-2:2017 specifies a standardized method for measuring the pH value of dispersions and coating materials (paints and varnishes) using pH electrodes with ISFET (ion‑sensitive field‑effect transistor) technology. It defines the measurement principle, required apparatus, calibration and cleaning procedures, sampling references, test conditions and reporting elements to ensure reproducible, comparable pH results for industrial and laboratory use. This part complements ISO 19396‑1, which covers pH measurement using glass‑membrane electrodes.
Key technical topics and requirements
- Scope and principle: Measurement of pH in polymer dispersions and coating formulations using combined ISFET + reference electrode assemblies (integrated temperature sensor recommended).
- Apparatus and materials:
- pH meter suitable for ISFET electrodes.
- ISFET electrode (measuring ISFET + reference electrode in one unit).
- At least two certified buffer solutions for calibration.
- Containers, deionized water, cleaning solution, stirring tools and optional thermostat/stand.
- pH meter functional requirements:
- pH reading accuracy of 0.01 pH.
- pH‑proportional voltage measurement accuracy of at least 1 mV.
- Ability to adjust offset (zero point) and practical slope, and to display measuring temperature.
- Manual or automatic temperature compensation (internal or external sensor).
- Calibration and verification:
- Use traceable buffer solutions with known temperature dependency.
- Calibrate offset and practical slope; monitor electrode slope against the theoretical slope (k = −58.57 mV at 23 °C).
- Sampling and preparation: Follow ISO 15528 (sampling) and ISO 1513 (sample preparation) because handling, transport and preparation impact pH results.
- Procedure and reporting: Specifies test conditions, number of determinations, stability requirements, and elements to include in the test report.
Practical applications and who uses this standard
ISO 19396-2:2017 is intended for:
- Quality control and production laboratories in paints, coatings and varnish manufacturing.
- R&D and formulation scientists measuring pH of dispersions and coatings.
- Third‑party testing labs performing conformity checks or interlaboratory comparisons.
- Instrument and electrode manufacturers developing or validating ISFET pH electrodes for industrial coatings.
Benefits include harmonized pH measurement procedures, better comparability of results across labs, and guidance for calibration and equipment requirements.
Related standards
Keywords: ISO 19396-2:2017, pH measurement, ISFET electrode, paints and varnishes, pH electrodes, buffer solutions, pH meter, coating materials.
Open preview (PDF)Paints and varnishes — Determination of pH value — Part 2: pH electrodes with ISFET technology