Overview
ISO 6270-2:2017 - "Paints and varnishes - Determination of resistance to humidity - Part 2: Condensation (in‑cabinet exposure with heated water reservoir)" specifies general conditions and procedures for exposing coated test specimens to condensation (in‑cabinet) humidity tests. The purpose is to ensure reproducible results between laboratories when testing in constant or alternating condensation‑water atmospheres. The standard defines test atmospheres, apparatus and basic procedure requirements but does not cover specimen shape, preparation, test duration or final assessment criteria.
Key topics and technical requirements
- Test atmospheres: three designated types - CH (constant humidity), AHT (alternating humidity and air temperature) and AT (alternating air temperature). Cycle times are typically 24 h (shorter cycles such as 12 h or 16 h are allowable by agreement).
- Chamber conditions: atmospheric temperature in the climatic chamber during condensation is (40 ± 3) °C. Relative humidity for the condensation phase is approximately 100% with condensation on specimens.
- Apparatus: a vapour‑tight climatic chamber with corrosion‑resistant inner surfaces and a floor trough (heated water reservoir) for generating condensation. The water depth in the trough shall be at least 10 mm during operation; water temperature preferably ≤ 60 °C to avoid excessive vapour formation.
- Installation: chamber installed in a non‑corrosive ambient room, typically (23 ± 5) °C and ≤ 75 % RH (for comparison tests, (23 ± 2) °C per ISO 3270).
- Procedure essentials: filling the trough, arranging specimens on a corrosion‑resistant rack, ensuring condensation forms on all specimens, running specified cycle(s), and recording the quantity of condensate where required.
- Limitations and reporting: temperature and humidity strongly influence outcomes. Any agreed deviations from standard conditions must be reported. The standard also adds methods for determining condensate quantity and includes information on precision.
Applications and who uses it
ISO 6270-2 is used for humidity and condensation testing of coatings to detect defects and evaluate resistance to humid environments. Typical users:
- Coating and paint manufacturers (R&D and quality control)
- Independent test laboratories and certification bodies
- Automotive, aerospace, marine and industrial OEMs specifying coating performance
- Corrosion and materials testing laboratories
- Standards committees and specifiers creating product or procurement requirements
Note: conditioning per ISO 6270-2 is intended to reveal humidity‑induced defects; it does not in itself provide lifetime prediction data. Evaluations after exposure are usually made using agreed procedures such as ISO 4628.
Related standards
- ISO 4628 (assessment of degradation and failure of coatings)
- ISO 3270 (temperatures and humidities for conditioning and testing)
- ISO 4618 (paints and varnishes - terms and definitions)
- Other parts of the ISO 6270 series
Keywords: ISO 6270-2:2017, condensation test, resistance to humidity, paints and varnishes, climatic chamber, condensation‑water atmosphere, humidity testing, coating performance.