For practical engineering applications creep and creep-fatigue occur in inherently harsh, high-temperature environments. There is a strong industry demand for continuous measurements to allow a better understanding of component integrity in a situation where outages allowing inspection are infrequent. A potential drop (PD) monitoring technique has been developed which enables the continuous monitoring of the integrity of high temperature components.
Electrodes are permanently attached to the surface of the component and a quasi-DC resistance measurement is taken. Defects in the material cause electrical current to be deflected and the resistance increases. This measurement technique requires only simple electrodes to be attached to the component and so the design is simple and robust.
In this project the fundamental understanding of Potential Drop measurements has been advanced, a measurement system with unique capabilities has been developed and the technique is being trialled at two UK power stations.