MEASUREMENT OF MAGNETIC FIELD DISTRIBUTION NEAR SMARTPHONE SCREENS BASED ON THE HALL EFFECT

In the 21st century, in the internet age where information grows explosively, smartphones play a crucial role in modern people’s daily lives. When smartphones are on standby or being charged, they generate a weak magnetic field, which may affect the surrounding environment and human health. This paper, based on the Hall effect and using 3D platform positioning as well as symmetric measurement methods, measured the magnetic flux density near the screens of two brands of smartphones in both standby and charging states. Results showed that both the distribution and intensity of the magnetic fields of the two different brands and models of phones differed significantly, and the distribution was related to the internal structure of the phones. For Huawei phones, the maximum magnetic flux density in standby and charging states was 2.13 mT and 3.33 mT, respectively, while for Apple phones, the corresponding values were 5.50 mT and 5.97 mT. Compared to standby mode, when being charged, the magnetic flux density on the screen surface of both brands of phones was higher. In addition, the magnetic flux density of the magnetic field on the surface of both types of phones decreased exponentially with increasing distance. The findings are significant for exploring the relationship between mobile phone magnetic fields and human health, charging induction electromagnetic characteristics, and electromagnetic compatibility design.