Which Portable Reference Electrode is commonly used on land away from seawater?

The choice of the correct portable reference electrode for use on land away from seawater is the Copper-Copper Sulfate Electrode (CSE). This electrode type is particularly suitable in environments where seawater is not present because it provides a stable and reliable potential in soil or other terrestrial settings that may not have the electrical characteristics of seawater.

The CSE is commonly used in many cathodic protection applications due to its relatively simple field use and its ability to maintain a stable reference potential even in varying soil conditions. It is effective for measuring the potential of metallic structures, ensuring that cathodic protection systems are functioning properly.

The other electrodes listed, while they may have their specific applications, are generally not used as conventionally as the CSE for land-based applications. The Saturated Calomel Electrode (SCE), for example, is sensitive to changes in ionic strength and may not perform as well in all soil types. The Standard Hydrogen Electrode (SHE) is primarily of theoretical interest and not often used in practical applications due to its complex handling requirements. Therefore, in typical practice on land, the CSE stands out as the most reliable choice.