---
type: "WebPage"
title: "Free potential measurement (OCV) in laboratory – electrochemical testing"
description: "You wish to perform a free potential measurement (OCV) What is the free potential measurement (OCV)? The measurement of free potential, also called open circuit voltage (OCV), is a non-intrusive electrochemical technique allowing to evaluate the electrochemical equilibrium state of..."
resource: "https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/free-potential-measurement-ocv/"
tags: ["EN", "pll_6855575b82951"]
timestamp: "2025-12-31T08:32:28Z"
published: "2025-06-20T13:24:54Z"
language: "en"
author: "Laure Durieux"
---

# Free potential measurement (OCV) in laboratory – electrochemical testing

## You wish to perform a free potential measurement (OCV)

### What is the free potential measurement (OCV)?

The measurement of free potential, also called open circuit voltage (OCV), is a non-intrusive electrochemical technique allowing to evaluate the electrochemical equilibrium state of a system without applying current.

It is commonly used to characterize electroactive materials, anti-corrosion coatings or even batteries and fuel cells.

[Electrochemical characterization](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/) and free potential measurement (OCV) 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), through [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).

## Why perform a free potential measurement (OCV)

##

 Free potential measurement (OCV) 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

Control the degradation of electrolytes, batteries or sensors

Study diffusive, capacitive or resistive behaviors in a system

## The FILAB laboratory supports you in measuring free potential (OCV)

## Why choose FILAB for free potential measurement (OCV)

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 free potential measurement (OCV) and electrochemical characterization of your metal parts.

## ANALYTICAL TECHNIQUE

Electrochemical free potential measurement (OCV) 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 evaluating the stability of protective coatings by providing valuable information on long-term mechanisms.

### Why perform a free potential measurement (OCV)?

  free potential measurement
##

 It is a key step to validate material choices, monitor corrosion phenomena, or even characterize electrochemical devices for R&D or quality control purposes. The measurement of free potential provides valuable information on:
Évaluer la [tenue à la corrosion](https://filab.fr/nos-prestations/expertise/laboratoire-analyse-depot-pollution/essai-tenue-corrosion.md) d’un [métal](https://filab.fr/nos-prestations/analyse/laboratoire-analyses-metallurgiques/laboratoire-analyse-metaux.md) ou d’un [alliage](https://filab.fr/paroles-d-expert/metallurgie-fonderie-automobile/filab-caracterise-vos-ferroalliages.md)

Tester l’efficacité d’un revêtement anticorrosion ou d’une peinture

Caractériser des films passifs sur des [surfaces](https://filab.fr/nos-prestations/analyse/caracterisation-de-surface.md) métalliques

Contrôler la dégradation d’électrolytes, [batteries](https://filab.fr/nos-prestations/expertise/analyse-caracterisation-materiaux-batterie.md) ou capteurs

Étudier des comportements diffusifs, capacitifs ou résistifs dans un système

Ensure the durability and reliability of materials

Encourage innovation and compliance

Know the initial behavior of an electrochemical system before any solicitation

### Common applications of free potential measurement (FPM)

  Batteries and accumulators: validation of the initial OCV, aging Anti-corrosion coatings: evaluation of passive protection Material development: study of interface reactions Industrial maintenance: diagnosis of defective electrochemical systems
## our electrochemical analysis services

[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)

Characterization of protective properties: barrier properties, porosity, water permeability, delamination, filamentary corrosion... ,

[Impedance measurement](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/electrochemical-characterisation-analysis-laboratory/impedance-measurement/) to analyse the properties of the interfaces between a material and its electrochemical environment

[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)

Development of specific electrochemical tests (cathodic delamination, ACET, corrosion at the edges ...)

## FAQ

 In which industrial fields is the OCV measurement used?
The measurement of free potential is used in many sectors:

- Energy (batteries, fuel cells) Aeronautics & automotive (corrosion of alloys)
- Medical devices (biocorrosion)
- Cosmetic & pharmaceutical (packaging materials)
- Nuclear & defense (stability control of sensitive materials)

 What is the difference between OCV and other electrochemical tests?
Unlike techniques such as linear polarization or EIS (electrochemical impedance), OCV does not stress the system. It is a passive measure, often used as a prior step or as a reference indicator.

 What conditions can influence the measurement?
Several parameters are to be controlled:

- Composition of the electrolyte
- Temperature
- Sample surface preparation
- Type and position of the electrodes

At the FILAB laboratory, these parameters are rigorously controlled to ensure the reliability of the results.