Verification of Electromagnetic Field Measurements via Inter-laboratory Comparison Measurements

Abstract

An inter-laboratory comparison of field strength measurements was conducted in order to verify the comparability of high-frequency electromagnetic field measurements. For this purpose, 17 participating teams hosted by the working group "procedures of exposure determination" of the LAI (Länderausschuss für Immissionsschutz, state committee on immission control) determined the field strength at given stations around a hospital situation. At those stations very different signals were generated, such as sine wave signals at 27MHz and 433MHz, signals from a diathermy device in Continuous-Wave (CW) and Pulse-Width-Modulation (PWM) mode, from a GSM base station at 900MHz and 1800MHz, from a UMTS base station, from a babyphone device and from a DECT cordless phone. This contribution describes the evaluation of the measured values and the approach to the computation of a reference value. Considering various sources of electromagnetic fields in the areas of personal safety at work and of immission control, the most important results are presented and the conclusions drawn are discussed.