Which reference electrode is most commonly used on land?

The copper-sulfate electrode (CSE) is the most commonly used reference electrode on land for several reasons. Primarily, it offers a stable and well-defined potential, which is essential for accurate measurements in cathodic protection systems. The CSE is composed of a copper electrode immersed in a saturated solution of copper sulfate, allowing it to establish a reliable electrochemical environment. This stability makes it ideal for use in various soils and conditions encountered in outdoor applications.

Moreover, the CSE is readily available and relatively easy to handle, making it a practical choice for field tests. It also maintains consistent performance even when exposed to different temperature ranges, which is a critical factor for on-site testing.

While other electrodes like the calomel electrode can be used, they are less common on land due to susceptibility to temperature changes and the need for careful handling because of their mercury content. Chromate electrodes, while effective in certain applications, are less frequently used due to environmental concerns and regulatory issues. Therefore, the copper-sulfate electrode stands out as the preferred option for most land-based cathodic protection testing.