Guarded Double Field Meter

Abstract

An instrument is described for absolute measurements of components of electrostatic fields in the free atmosphere near the earth's surface. This apparatus provides a guarding system to minimize field distortion at the measurement site. A method utilizing models in an alternating electric field is used to evaluate the augmentation factor of the instrument as well as the effectiveness of the guarding system. The instrument has been used to measure horizontal electric field and to make vertical field profiles. It is also used simultaneously with a field meter flush with the earth to make an analog record of space charge density.