Measurement Time Reduction in Compliance Assessment of Electromagnetic Field Levels

Abstract

International and national guidelines require a 6-minute temporal averaging of the measured signal when assessing the compliance of electromagnetic field levels for human safety. Spatial averaging is also required to account for total body exposure. When a telecom operator or governing authority wants to addressing public concern, the measurements have to be conducted at lots of locations. Hence, the measurement campaign tends to be time-consuming and costly. This paper presents an algorithm for reducing the measurement time when evaluating the compliance of electromagnetic fields radiated by telecom operators. The algorithm is based on moving quadratic average and is suitable for averaging the volatile measured signal. The post-processing of the measured signal results in an empirical model for selecting a shorter averaging time with an acceptable accuracy. Several measurements in outdoor and indoor scenarios have been performed with a calibrated wideband probe on the campus of Ferdowsi University of Mashhad. The processing of the results based on the presented algorithm show that a 1 minute rms value is adequate to obtain the field level with practically less than 5% accuracy. This significantly reduces the measurement time and associated expenses.