Using reference electrodes to monitor the electrochemical potential of steel reinforcement in concrete is a well established technique for assessing the severity of corrosion and for controlling cathodic protection systems. This report gives a state-of-the-art overview of the electrochemical and physical characteristics and performance of embeddable reference electrodes for concrete, and the method used for installing them.The report first reviews electrochemical potential and reference electrodes in general. It then assesses the different types of reference electrodes for concrete. Finally, it considers key issues such as location and quality control which need to be considered when installing reference electrodes in steel-reinforced concrete structures.