Factors Affecting the Accuracy of Reference Electrodes

This article discusses several factors that affect the reference potential established by silver/silver chloride and copper/copper sulfate reference electrodes. Data is presented on the effects of temperature, light, contaminants and solute concentration. hen measuring corrosion potential, a voltmeter is used to measure the potential (voltage) between the structure and a reference electrode placed in the same electrolyte. The entire circuit, structure plus reference, can be thought of as a single cell. Because a reference electrode comprises one half of this cell, it is commonly referred to as a "half cell". Measured potentials are actually the difference in potential between that of the reference and that of the structure. It is frequently assumed that the potential established by a reference electrode is absolutely invariant; therefore, any observed potential changes must be occurring on the structure. This is not always the case. The observed changes could also be caused by a change in the reference while the structure remains steady. To ensure accurate potential measurements, it is important to understand those factors that affect the potential established by a reference electrode