2007 International Workshop on Health Effects on EMF

2007 International Workshop on Health Effects on EMF Bioelectromagnetic Environment Development of ELF Magnetic Field Exposure Recording System Ho-Sang Yoo*, Geun-Mee Seo* , Jin-Yong Kim**, Yoon-Myoung Gimm**, Jae-Joon Kimo, Tae-Kyu Leeo, Koo-Yong Shinoo *Dept. of ECE, Graduate School, Dankook University, Seoul, S. Korea **EMF Safety Inc. , Seoul, S. Korea o. Korea Electronic Power Corporation, Seoul, S. Korea oo. Korea Electric Power Research Institute, Daejeon, S. Korea September 6, 2007 Seoul Educational & Cultural Center, Seoul, S. Korea (首爾 敎育 文化 會館 )

Outline u What’s the Issue in ELF Magnetic Field ? u Conventional ELF Magnetic Field(MF) Measurement System u Characteristics of MF near Power Lines u New ELF Magnetic Field Exposure Recording System (Mag. Pos) - Block Diagram, Specification, etc. u Test Result of Mag. Pos - KRISS Certificate Test, Trace Test etc. u Patents - Korea & PCT Patents u Conclusion 2

What’s the Issue in ELF Magnetic Field ? u Controversy on ELF magnetic field : Child leukemia (IARC Class 2 B). u Trend of adopting precautionary policies in some countries. u Requirement to measure personal exposures for the epidemiology. u Measurement of position and time together with the ELF magnetic field(MF) for the convenient analysis. u A new system which is able to save the magnetic field, the measurement position, and the measurement time simultaneously is required. 3

Conventional ELF MF Measurement System MF : Magnetic Field HI-3604 (Holiday Industries) EMDEX (Enertech) EFA-300 A (Wandel Goltermann) 4

Characteristics of MF near Power Lines Biot-Savart’s Law B : magnetic flux density (Wb/m 2) μo : permeability in vacuum (N/A 2) I : current along the line (A) r : distance from the source line (m) B is the function of current I and distance r. 5

New ELF MF Exposure Recording System (Mag. Pos) B Field Mode GPS Mode Mag. Pos LOG Mode Config Mode 6

System Block Diagram of Mag. Pos 7

System Specification of Mag. Pos Item Specification Measurement Direction 3 -Axes, Isotropic Range 0. 01 - 100. 0 µT (0. 1 - 1000 m. G) Resolution 0. 01 µT (0. 1 m. G) Typical Accuracy ± 0. 01 u. T ± 3 % @ 60 Hz Frequency Range 40 ~ 300 Hz @ 3 d. B Sample Rate (per an axis) 0. 9 sec – 2. 7 sec (depends on MFD) Internal Memory Measurement Record No. Display Log data 388, 800 Byte Location memory 800 Byte Log data 21, 600 Location memory 100 Graphic (128*64 dots) LCD 8

System Specification of Mag. Pos-cont. Item Specification Measurement Method True RMS Battery Life (Typical) Above than 6 days (8 hours a day) @ All Operation ON External Charging Voltage 4. 2 VDC Inside Battery Type Rechargeable Lithium-ion Dimensions 82 mm * 178 mm * 38 mm (H * V * D) Weight 318 gram Operating Temperature +10℃ ~ +40 ℃ Operating Humidity 5 % ~ 90 % Display Time Interval 1 sec 9

3 -axes Magnetic Field Sensor in Mag. Pos Magnetic Field Sensor Magnetic Flux Line near a Ferrite Core 3 -axes Magnetic Flux Density Faraday’s Electromagnetic Induction law V : induced voltage (V) ω : angular frequency (radian/sec) N : number of turns S : loop area (m 2) B : magnetic flux density (Wb/m 2) Bx, By, Bz, : RMS value of three axes magnetic flux density (Wb/m 2) : three axes unit vectors α, β : phase difference between axes (radian) ω : angular frequency (radian/sec) 10

Circuit Linearization for Wide Dynamic Range Magnetic Flux Density Multiplexer Selection Gain of Gain Control Amp. 0. 01 μT ~ 1. 00 μT S 0, S 2, S 4 High Gain 1. 00 μT ~ 10. 0 μT S 0, S 2, S 4 Low Gain 10. 0 μT ~ 100. 0 μT S 1, S 3, S 5 Low Gain 11

Development Environment of Mag. Pos Magnetic Flux Line of Magnetic Field Generation Coil 12

Test Environment for Certification in KRISS : Korea Research Institute of Standards and Science 13

Certification Test Result of Mag. Pos by KRISS Magnitude Response Frequency Response 14

Comparative Test of MAGPOS and EMDEX Mag. Pos Magnetic Flux Density (u. T) EMDEX Input Voltage to Magnetic Field Generation Coil (m. Vrms) Test Setup Test Result 15

Trace for Recording Environmental Magnetic Field Dankook Univ. EMF Safety Address : Eongo Building 7 th Floor, start 72 -17 Hannam-dong 1, Yongsan-gu, Seoul, South Korea 16

Environmental MFD : Magnetic Flux Density (u. T) 17

Environmental MFD Measurement Result along the Trace Line Blue Color : 0. 00~0. 39 u. T Yellow Color : 0. 40~0. 99 u. T Red Color : Above than 1. 00 u. T 18

Pending Korea and PCT Patent 19

Conclusion u New ELF magnetic field recording system (Mag. Pos) was developed. u Mag. Pos saves the magnetic field, the measurement position, and the measurement time simultaneously. u Measurement range : 0. 01 ~ 100. 0 u. T (0. 1 ~ 1000 m. G). u Measurement frequency band : 40 ~ 300 Hz @ 3 d. B. u GUI(Graphic User Interface) is easy and convenient to analyze personal exposures. 20