Calibration of atmospheric electric field meters and the determination of form factors at Kennedy Space Center

The calibration of atmospheric electric field meters requires the generation of an electric field of a known strength. The most common device used to produce a homogeneous or constant electric field is the plate condenser. However, because of the edge effect and particularly due to the influence of grounded walls surrounding the plate condenser, the field in the outer regions of the plate condenser is distorted so that only in a certain central region does a homogeneous field exist. This distortion may penetrate the plate condenser completely so that a homogeneous field does not exist anywhere. Under these circumstances, it is extremely difficult to obtain an absolute calibration. Another problem arises from the field distortion induced by the instrument itself. To minimize the influence of this distortion, certain dimensions of the plate condenser are required as discussed in section 2.