Schneeweiss Pia, Hirtl Rene, Schmid Gernot
Seibersdorf Laboratories, Department EMC & Optics, A-2444 Seibersdorf, Austria.
J Radiol Prot. 2023 Feb 21;43(1). doi: 10.1088/1361-6498/acb955.
In order to evaluate the localised magnetic field (MF) exposure of the cashier's hand due to a particular demagnetization device (deactivator) for single-use labels of an acoustomagnetic (AM) electronic article surveillance (EAS) system, comprehensive measurements of the MF near the surface of the deactivator, and numerical computations of the induced electric field strength, were performed in high-resolution anatomical hand models of different postures and positions with respect to the deactivator. The measurement results for magnetic inductionwere assessed with respect to the action levels (AL) for limb exposure, and the computational results forwere evaluated with respect to the exposure limit values (ELV) for health effects according to European Union (EU) directive 2013/35/EU. For the ELV-based assessment, a maximum of the 2 × 2 × 2 mmaveraged(max) and the respective 99.9th, 99.5th, and 99.0th percentiles were used. As the MF impulse emitted by the deactivator for demagnetization of the AM-EAS labels was highly nonsinusoidal, measurement results were assessed based on the weighted peak method in the time domain (WPM-TD). A newly developed scaling technique was proposed to also apply the WPM-TD to the assessment of the (nonsinusoidal)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 cmMF 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 ofas the AL were intentionally defined conservatively. A WPM-TD-based assessment offinally led to the worst case EI of up to 135%, 93%, 78%, and 72% when using the max, 99.9th, 99.5th, and 99.0th percentiles, respectively.
为了评估特定的一次性声磁（AM）电子商品防盗（EAS）系统标签消磁装置（去激活器）导致收银员手部局部磁场（MF）暴露情况，在不同姿势和相对于去激活器不同位置的高分辨率手部解剖模型中，对去激活器表面附近的MF进行了全面测量，并对感应电场强度进行了数值计算。根据肢体暴露的行动水平（AL）评估磁感应测量结果，根据欧盟（EU）2013/35/EU指令，针对健康影响的暴露限值（ELV）评估计算结果。对于基于ELV的评估，使用了2×2×2毫米平均最大值（max）以及各自的第99.9、99.5和99.0百分位数。由于去激活器为AM-EAS标签消磁所发射的MF脉冲高度非正弦，基于时域加权峰值法（WPM-TD）评估测量结果。提出了一种新开发的缩放技术，以便将WPM-TD也应用于关于ELV的（非正弦）评估。它用于根据频域计算得出基于WPM-TD的暴露指数（EI）。关于肢体AL的评估得出磁感应峰值高达97 mT（在去激活器表面顶部用3厘米MF探头测量），对应EI为443%。然而，由于AL是故意保守定义的，就实际暴露而言，这被认为是对实际暴露的高估。基于WPM-TD的最终评估在分别使用最大值、第99.9、99.5和99.0百分位数时，最坏情况下EI分别高达135%、93%、78%和72%。
