スマートメータの通信に用いられるRF電磁界の人体ばく露における数値モデルの構築と評価

抄録

We assessed human exposure to radiofrequency (RF) electromagnetic fields used for a wireless communication system installed on a smart meter for communication in the 920 MHz band. In an exposure guideline, the specific absorption rate (SAR) is used as a measure of the thermal effects of human exposure to electromagnetic fields. Although the low-power wireless communication device used for the smart meter inherently complies with the exposure guideline, the assessment of the RF electromagnetic field exposure is useful to deepen our understanding of human safety. For the exposure assessment, firstly, a computational smart meter model was constructed and validated by comparison with the measured data of electric fields around an actual smart meter. Using the computational smart meter model, we calculated the SAR in the head of an anatomical human model that was located very close to the smart meter. The maximum SAR in the head was obtained when the antenna was placed in front of a human eye, which was calculated to be 10.3 mW/kg for an input power of 20 mW. It was shown that the maximum SAR was 200 times smaller than the basic restriction level in the exposure guideline.