Analytic functions are derived for the spectral noise voltage density between two circular sensor electrodes on a two-dimensional isotropic conductor, placed either transversely or longitudinally to a homogeneous electric field. The sensor electrodes are far removed from both the bias electrodes and the boundaries. The relations have been checked experimentally for 1/ f conductivity fluctuations. Both the transverse and longitudinal noise are proportional to I -2L(J·J)2 ds where J.j represents

more »

... he dot (scalar) product of the homogeneous current density J and the adjoint current density j, and the current through the bias electrodes is I. It is found that the transverse noise is somewhat smaller than the longitudinal noise.