--- type: "WebPage" title: "Impedance measurement in laboratory – electrochemical test" description: "You wish to perform an impedance measurement of your materials What is the impedance measurement? Electrochemical impedance measurement (EIS) is a non-destructive, extremely sensitive analysis method that allows the characterization of the electrochemical properties of a material or a system..." resource: "https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/impedance-measurement/" tags: ["EN", "pll_6852d21ef0ebe", "Anaïs DECAUX"] timestamp: "2025-12-31T08:32:28Z" published: "2025-06-18T15:28:45Z" language: "en" author: "Laure Durieux" --- # Impedance measurement in laboratory – electrochemical test ## You wish to perform an impedance measurement of your materials ### What is the impedance measurement? **Electrochemical impedance measurement (EIS)** is a **non-destructive**, extremely sensitive analysis method that allows the **characterization of the electrochemical properties** of a material or a system as a function of the excitation frequency. It aims to detect defects in protective coatings, evaluate the homogeneity of the layers and study surface [corrosion](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/laboratory-expertise-and-analysis-of-corrosion.md) phenomena. [Electrochemical characterization](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/) and impedance measurement can be applied to many industrial sectors, from [aeronautics](https://filab.fr/en/sectors-of-activity/laboratory-analysis-aeronautics-aerospace.md) to [cosmetics](https://filab.fr/en/sectors-of-activity/laboratory-analysis-cosmetics.md), including [energy](https://filab.fr/en/sectors-of-activity/laboratory-analysis-nuclear-energy.md) and [medical devices](https://filab.fr/en/sectors-of-activity/laboratory-analysis-medical-devices.md). ## The FILAB laboratory supports you in the impedance measurement of your materials ## Why choose FILAB for impedance measurement? FILAB, a laboratory made up of experts in [metallurgy and steelmaking](https://filab.fr/en/sectors-of-activity/laboratory-metallurgy-steelmaking-analysis.md) analysis, provides its knowledge and expertise to carry out impedance measurement and electrochemical characterization of your metal parts. To support you in the best conditions, the FILAB laboratory is approved [Research Tax Credit (CIR)](https://filab.fr/en/filab-cir-approved-analysis-laboratory.md) and accredited [COFRAC ISO 17025](https://filab.fr/en/about-us/accreditations-en/laboratory-analysis-iso-17025.md). ### Why perform an electrochemical impedance measurement? impedance measurement ## Impedance measurement is particularly relevant for: Evaluate the [corrosion resistance](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/corrosion-resistance-testing.md) of a [metal](https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/laboratory-analysis-metals.md) or an [alloy](https://filab.fr/en/analysis-of-metallic-alloys-in-the-laboratory.md) Test the effectiveness of an anticorrosive coating or a paint Characterize passive films on metal [surfaces](https://filab.fr/en/our-services/our-analysis-services/laboratory-surface-characterization.md) Control the degradation of electrolytes, [batteries](https://filab.fr/en/our-services/our-expertise-services/analysis-characterization-battery-materials.md) or sensors Study diffusive, capacitive or resistive behaviors in a system ## ANALYTICAL TECHNIQUE Electrochemical impedance is a **non-destructive** method that analyzes the properties of **interfaces between a material and its electrochemical environment**. By applying an alternating signal, it measures the resistance and ability of a system to conduct loads. This technique is essential for :  - Assess the long-term stability of coatings used on aluminium or titanium alloys, - Compare several solutions with a view to replacing chromium VI, - Monitor the accelerated ageing of parts or assemblies under simulated conditions. ### Why perform an impedance measurement? Performing an **impedance measurement – electrochemical analysis** on materials allows meeting industrial challenges: Ensure the durability and reliability of materials Impedance measurement identifies degradation mechanisms, such as corrosion, and allows for the selection or improvement of materials to better withstand specific conditions. Optimize performance and reduce costs This measure also allows the development of **more efficient materials (conductivity, resistance, protection)** and to prevent failures, thus reducing costs related to maintenance, replacement, and business interruptions. Encourage innovation and compliance Thanks to a better understanding of electrochemical reactions, industrialists can design innovative solutions (alloys, coatings) while ensuring that products comply with current standards. ## our electrochemical analysis services [Measurement of the free potential (OCV)](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/free-potential-measurement-ocv/) to evaluate the spontaneous electrochemical behavior of a metal in a given medium (water) [Study of galvanic coupling](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/galvanic-coupling-testing/) in order to analyze the interactions between two metallic materials to identify differential corrosion risks (ex: Zinc vs Steel) Characterization of protective properties: barrier properties, porosity, water permeability, delamination, filamentary corrosion... , [Determination of the corrosion rate (LSV)](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/study-corrosion-speed/) in order to know the corrosion rate (mm/year) in various environments (salt water, pure water, inhibitor presence) Measurement of corrosion potential (polarization curves) [Potensiostat](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/potensiostat-analysis/) Development of specific electrochemical tests (cathodic delamination, ACET, corrosion at the edges ...) ## FAQ Which materials can be analyzed by impedance measurement? The impedance measurement applies to: - Bare or treated metals (steel, stainless steel, aluminium, copper, titanium, etc.) - Organic coatings (paints, varnishes, polymers) - Surface treatments (anodisation, passivation, phosphatization, etc.) - Composites or functional materials (batteries, electrodes, sensors...) What is the interest of impedance measurement compared to a classic corrosion test? Unlike destructive tests like salt spray, the EIS is non-destructive, fast and more sensitive. It allows for: - Detect the first signs of degradation before they are visible - Compare systems or formulations without waiting several weeks of testing - Follow the evolution of a material over time What are the standards applicable to impedance measurement? Depending on the sector, several standards can frame the trial: - ISO 16773: for organic coatings on metals - ASTM G106 / G200: for corrosion by EIS - Client internal standards or specific R&D protocols Environments concerned by impedance measurement Electrochemical interactions between materials occur in a variety of natural and industrial environments: - Aqueous environments, such as seawater, favour phenomena such as galvanic corrosion due to the presence of ions. - Humid or polluted atmospheres, rich in humidity and pollutants such as salt or sulphur dioxide, also accelerate the degradation of materials, particularly in marine or industrial areas. - Acidic or alkaline environments, with an extreme pH, and high-temperature environments encountered in the chemical or petrochemical industries, intensify electrochemical reactions. - Controlled electrochemical environments, used in processes such as electrolysis or electroplating, illustrate the importance of anticipating these interactions to guarantee the durability of materials under specific conditions.