Spherical field meter for measurement of the electric field vector

Abstract

A spherical field meter has been designed, constructed, and calibrated for the measurement of the atmospheric electric field vector above the ground surface. Three different insulated quadrants of a conductive sphere are used to measure the electric field normal to the quadrants. These three outputs together with nine field-distortion coefficients, determined experimentally, are used to determine the three components of the electric field, and hence, the electric field vector. The instrument can detect electric field changes of 2 V/m or more in any one component of the electric field and is reasonably stable for continuous operation. Preliminary observations show that variations in the vertical components of the electric field measured with the spherical field meter are parallel to the ones measured by a radioactive probe and the horizontal field components may be appreciable. Limitations of the apparatus and some possible modifications to it are discussed.