The potential displacemeter is the gauge for monitoring displacements of embankment and rockfill dams. A brief introduction is given to the function of the potential displacemeter as well as its application in several dam projects. The TS soil displacemeter with single potential displacemeter being the core

applied in many core wall rockfill dams

might be employed to observe the shear displacement or tension displacement between the core wall and the concrete cushion

and deformation of the core wall is monitored in time. The TST face displacemeter with double potential displacemeters being the core is employed to monitor separating deformation and shear deformation of faces so as to provide basis for the determination of treatment schemes and the treatment effectiveness of the separating faces. It has been successfully applied in high concrete face rockfill dams

which gives separating data and variation curves of faces in time. The TSJ joint meter with three potential displacemeters being the core is taken to monitor the opening and shear deformation of joints as well as the settlement deformation in the direction of vertical faces. It has been applied in many concrete face rockfill dams in China and has yielded the deformation and variation curves of joints in time

thus providing basis for the safety evaluation of dams.