Very small displacements, both static and dynamic, are normally generated by piezo actuators. High precision displacement sensors ensure that these displacements are measured to the required nanometre and sub-nanometre accuracies. Resolution and repeatability of up to 0.04nm are possible. Non-contact, capacitive displacement sensors from Micro-Epsilon provide this sub-nanometre precision. The capaNCDT series combines high precision and the required stability.