Hot-dip galvanised steel and electrogalvanised steel are widely used in the automotive and construction industry. The corrosion testing of these metallic coatings includes exposure at natural weathering sites and exposure in cyclic corrosion tests in the laboratory. The corrosion rate is then evaluated using mass loss measurements and visual observations such as time to red rust. In this work we have developed a new sensor based on electrrical resistance measurements and applied it on galvanised steel. This new device allow in-situ and real time measurements of the corrosion rate of galvanised steel. Exemple of utilisation of the sensor in cyclic corrosion tests will be given. The new device offer the possibility to better undertand the different phases of cyclic corrosion testing with the ultimate goal to develop more relevant testing procedure. This provides new possibilities to study the atmospheric corrosion of metallic coated steel in various environments. Exemple of use in the case of painted steel will also be given.