DIN Standards Committee Coatings and Coating Materials
DIN EN ISO 13129
Paints and varnishes - Electrochemical measurement of the protection provided to steel by paint coatings - Current interrupter (CI) technique, relaxation voltametry (RV) technique and DC transient (DCT) measurements (ISO 13129:2012); German version EN ISO 13129:2012
Beschichtungsstoffe - Elektrochemische Messung der Schutzwirkung von Beschichtungen auf Stahl - Stromunterbrechungsverfahren (CI), Relaxationsvoltametrie (RV) und Gleichstromtransientenmessung (DCT) (ISO 13129:2012); Deutsche Fassung EN ISO 13129:2012
Quantitative assessment of protection performance of organic coatings has been required in industry, for example, for evaluating the durability of organic coatings or judging the life of protective coatings. Electrochemical methods can be used for these purposes. The current interrupter (CI) technique, relaxation voltammetry (RV) and DC transient (DCT) measurements are simple techniques giving effective data which are comparable with electrochemical impedance spectroscopy (EIS) in principle. An advantage is that the principle is simple and time for one measurement is short. This International Standard specifies the procedure for evaluation of the experimental set-up of electrochemical measurements on high-impedance coated samples using methods that are based on the current interrupter (CI) technique, relaxation voltammetry (RV) or DC transient (DCT) measurements. It provides specific definitions and guidance on optimizing the collection of CI, RV and DCT data from high impedance systems. High impedance in the context of intact coatings refers to systems with an impedance greater than 109 Ω/cm2. This does not preclude measurements on systems with lower impedance. This International Standard deals in particular with: - instrumental set-up: requirements and shortcomings; - data validation: checking the measurement range and the accuracy of the data; - performing CI, RV, DCT measurements: specimen considerations and instrumental parameters; - the experimental results: different methods of presenting CI, RV and DCT data. Following the recommendations should ensure the acquisition of CI, RV and DCT data that can be used to study the performance of the specimen. This International Standard does not give guidelines for the interpretation of these data. The committee responsible for this standard is NA 002-00-07 AA "Allgemeine Prüfverfahren für Beschichtungsstoffe und Beschichtungen" ("General test methods for coating materials and coatings") at DIN.