Practical Method to Evaluate the Effects of the Sensor and the Environment on the Measurement of Lightning-Generated Electric Field Signatures

Indirect lightning measurement, using sensors and remote systems that record the radiated electric fields, is one of the most used methods to study and characterize this type of electrical discharges. This is due to its simplicity of implementation, low cost and the valuable information it provides. However, the measurement of the lightning-generated electric fields (LEF) can be influenced by factors such as the type of sensor, its physical features and its location, as well as by characteristics of the electromagnetic environment like geographical features, the structures that surround the measurement station and the materials of these objects. Under this consideration, this paper proposes a generalized method focused on the identification of those parameters that affect significantly influence the LEF measurement, as well as the process to estimate the correction factor of any measuring system designed for this purpose. This factor is important, as it indicates the proportion in which the signals of interest are attenuated or amplified. The method includes a review about the characteristics of the sensors, their connection scheme and a detailed analysis of the effect of the surrounding structures, taking into account parameters such as the permittivity and electrical conductivity of the materials. Finally, with the aim of presenting quantitative results, the proposed method is validated using as a practical case the information from the LEF automated measuring station owned by the Universidad Distrital Francisco José de Caldas, located in Bogotá, Colombia

Permittivity measurement on construction materials through free space method

This paper presents the validation and test of an experimental set-up for complex permittivity measurements of construction materials. Measurements on reference materials like Plexiglas® and PVC in an anechoic chamber and in a laboratory set up give results in agreement with literature data. The proposed set up is able to accommodate walls made with different construction materials and to measure their complex permittivity as a function of the frequency in the 2 - 6 GHz range