Design and calibration of an atmospheric electric field sensor with wireless comunication

Abstract

The ability to evaluate the possibility of a lightning discharge is a important resource in making safety-related decisions, and enables the reduction of losses due to shutdowns in the energy sector, as well as other damages. The atmospheric electric field sensors are used to measure the magnitude of the electric field in a region between the earth and a storm cloud, and estimate how much the value of this field is approaching the threshold for an electric discharge. This paper presents the development of a sensor of electric field type EFM with two sets of 2-pole electrodes to the acquisition of differential current proportional to the electric field over the sensor. The data are sent in wireless way through a set of communication protocols called Zigbee, and are analyzed on an interface. The sensor calibration was performed using two conductive plates separated by a distance of 72.9 cm, by applying a DC voltage there between, producing an electric field theoretically known with normalized uncertainty. The prototype achieved through the method of validation the linearity between voltage on the plates, and the measured electric field with combined uncertainty for values greater than 593 V/m of 0.7% and for next values of 296 V/m of 1.1%, and a maximum expanded uncertainty of 2.2%.