Safety assessment of electromagnetic exposure of walk-through metal detectors operating at 6.48 kHz

Fig. 2. Simulation scenario of adults and children in the WTMD: (a), (b) in the middle; (c), (d) near the coil side

Fig. 3. Distribution of magnetic induction intensity for adults and children in the WTMD: (a)，(b) in the middle；(c)，(d) near the coil side

Fig. 4. Cross-sectional view of magnetic induction intensity distribution in the WTMD for adults and children：(a), (b) in the middle；(c), (d) near the coil side

Fig. 5. Cross-sectional view of the magnetic induction intensity distribution of the heads of adults and children in WTMD:(a),(b) in the middle；(c),(d) near the coil side

Fig. 6. The distribution of induced electric field strength for adults and children in WTMD:(a)，(b) in the middle；(c)，(d) near the coil side

Fig. 7. Cross-sectional view of the induced electric field intensity distribution in WTMD for adults and children: (a)，(b) in the middle；(c)，(d) near the coil side

Fig. 8. Cross-sectional of the distribution of the induced electric field in the head for adults and children in WTMD：(a), (b) in the middle；(c), (d) near the side of the coil

Table 1. Dimensions of major body parts for adults and children

Table 1. Dimensions of major body parts for adults and children

人体

Human

头部 / m Head

躯干 / m Body

R₁

R₂

R₃

L₁

L₂

L₃

L₄

L₅

L₆

L₇

L₈

成年人 Adults

0.080 0

0.085 0

0.092 0

1.750

0.037 5

0.20

0.560

0.68

0.93

0.23

0.03

儿童 Children

0.058 8

0.062 4

0.067 6

1.229

0.025 0

0.16

0.425

0.45

0.62

0.15

0.02

Table 2. Human important tissues permittivity and conductivity at 6.48 kHz

Table 2. Human important tissues permittivity and conductivity at 6.48 kHz

组织 Tissue	相对介电常数 Relative permittivity	电导率 / (mS‧m^－1) Conductivity
头皮 Scalp	1 134.3	0.201 87
颅骨 Skull	1 531.7	5.140 05
大脑 Cerebrum	16 905.7	726.41
躯干 Body	8 438.7	194.573 17

Table 3. The maximum magnetic induction intensity inside the human body when adults and children are in different positions

Table 3. The maximum magnetic induction intensity inside the human body when adults and children are in different positions

模型 Model	位置 Location	磁感应强度 / μT Magnetic flux density	占ICNIRP限值的比率 / % Account for ICNIRP
成年人Adult	安检门中间In the middle of the WTMD	1.75	6.48
成年人Adult	安检门侧边In the side of the WTMD	2.44	9.04
儿童Children	安检门中间In the middle of the WTMD	1.02	3.78
儿童Children	安检门侧边In the side of the WTMD	1.86	6.89

Table 4. Electric field strength value inside the human body when adults or children are in different positions

Table 4. Electric field strength value inside the human body when adults or children are in different positions

模型	位置	感应电场强度 / (mV‧m^-1)	占ICNIRP限值的比率 / %
Model	Location	Induced electric field	Account for ICNIRP
成年人Adult	安检门中间In the middle of the WTMD	4.31	0.49
成年人Adult	安检门侧边In the side of the WTMD	4.97	0.57
儿童Children	安检门中间In the middle of the WTMD	2.32	0.27
儿童Children	安检门侧边In the side of the WTMD	3.12	0.36

Table 5. Electric field strength value inside the CNS tissue of the head when adults or children are in different positions