Fractal capacitive sensor and non-invasive voltage measurement apparatus incorporating same

A capacitive sensor 100 which may be used to measure AC and DC voltage non-invasively has a first conductive plate layer 102 and a second conductive plate layer 104 with a dielectric layer 106 sandwiched between them. Each of the first and second conductive plate layers or arrays have spaced apart conductive plates 108, 110 separated by dielectric gaps 107. The conductive plates on the first and second conductive plate layers are positioned opposite each other across the dielectric layer. The dielectric layer comprises a non-uniform material having either or both of a plurality of sections of dielectric material having different dielectric constants (fig 3), and conductive plates embedded in the dielectric layer 116. Preferably, the capacitive sensor is cylindrically shaped to enable a conductor under test to be received in a coaxial arrangement (fig 7). Also disclosed is a non-invasive voltage measurement apparatus.