Assessing non-sinusoidal in situ electric field strength inside a detailed anatomical hand model caused by a magnetic deactivator device for EAS labels.

To evaluate the localized magnetic field (MF) exposure of the cashier's hand due to a particular de-magnetization device (deactivator) for single-use labels of an acousto-magnetic (AM) electronic article surveillance (EAS) system, comprehensive measurements of MF near the surface of the deactivator and numerical computations of the induced electric field strength E i were performed in high-resolution anatomical hand models of different postures and positions with respect to the deactivator. The measurement results for magnetic induction B were assessed with respect to the action levels (AL) for limb exposure, and the computational results for E i were evaluated with respect to the exposure limit values (ELV) for health effects according to EU directive 2013/35/EU. For the ELV-based assessment, the maximum of the 2 x 2 x 2 mm 3 averaged E i (maxE i,avg ) and the respective 99.9 th , 99.5 th , and 99.0 th percentiles were used. As the MF impulse emitted by the deactivator for de-magnetization of the AM-EAS labels was highly non-sinusoidal, measurement results were assessed based on the weighted peak method in time domain (WPM-TD). A newly developed scaling technique was proposed to apply the WPM-TD also for the assessment of the (non-sinusoidal) E i regarding the ELV. It was used to calculate the resulting WPM-TD based exposure index (EI) from frequency domain computations. The assessment regarding the AL for limbs yielded peak values of magnetic induction of up to 97 mT (measured with a 3 cm 2 MF probe on top of the deactivator surface) corresponding to an EI of 443 %. However, this was considered an overestimation of the actual exposure in terms of E i as the AL were defined conservatively by intention. A WPM-TD based assessment of E i finally led to worst case EI up to 135 %, 93 %, 78 %, and 72 % when using the maxE i,avg , 99.9 th , 99.5 th , and 99.0 th percentiles, respectively.