Occupational Exposure to ELF Electromagnetic Fields

职业暴露于极低频电磁场

• 批准号: 12450111
• 负责人: ISAKA Katsuo
• 金额: $ 5.5万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450111/
• 关键词: Occupational exposure; ELF; Extremely low frequency; Electromagnetic field; Welding; Students experiment; Magnetic field measurement; Induced Current; 電気溶接; 磁界; 電界; ホール素子; 電磁界暴露評価; 磁界波形; 電力線; スペーサ点検; 職場; 暴露評価; 電力; VDT

On the basis of the experience of measuring electromagnetic exposures in the occupation sites like electric power, welding, electromagnetic induction heating, railroad and iron steel works, a survey was made of measuring the exposure of 7 students performing experiments in the lab time to magnetic fields. The five of them carried EMDEXII meters and the two EMDEX MATE meters during the lab. They also performed experiments associated with electric power systems. As a result, it has been found that time-weighted average of the exposure exceeds 100 μT for relay and welding experiments.A novel meter was developed for measuring the AC magnetic field superimposed on DC one that appears at the time of welding using a DC source. Some Hall elements were successfully connected in series to detect and observe such a magnetic field.In order to reduce the exposure of welders to magnetic fields, several mitigation measures were proposed : (1)A welder should be out of the loop line conductor carrying a welding current, (2)The line conductor should be close enough so that the magnetic fields are cancelled each other. (3)A long line conductor should not be placed in a loop manner on the ground. The impedance method was introduced to evaluate the induced current density in the welder. It is found from the computer simulation that this method is applicable to compare the maximum induced current to the basic restriction specified by ICNIRR.

根据在电力、焊接、电磁感应加热、铁路、钢铁等职业场所进行电磁暴露测量的经验，对7名在实验室时间内进行实验的学生进行了磁场暴露测量。他们五人在实验室中携带了EMDEXII仪表和两个EMDEX Mate仪表。他们还进行了与电力系统相关的实验。结果表明，在继电器和焊接实验中，曝光量的时间加权平均值超过100μT。为了测量直流电源焊接时产生的直流磁场，研制了一种新型的测量仪器。为了减少焊工对磁场的暴露，提出了几种缓解措施：(1)焊工应远离携带焊接电流的回路导线；(2)导线应足够近，以使磁场相互抵消。(3)长导线不应在地面上成圈放置。介绍了用阻抗法测量焊机感应电流密度的方法。计算机仿真结果表明，该方法适用于将最大感应电流与ICNIRR规定的基本限制进行比较。

项目成果

M. Akatani, Y. Yokoi and K. Isaka: "Development of an Instrument Used for line Insulation Diagnosis of House Wiring"Trans. IEE of Japan. 122-B, No.6. 710-717 (2002)

M. Akatani、Y. Yokoi 和 K. Isaka：“用于房屋布线线路绝缘诊断的仪器的开发”Trans。

赤谷, 横井, 伊坂: "屋内配線の活線絶縁診断装置の開発"電気学会論文誌. 122・6. 710-718 (2002)

Akaya、Yokoi、Isaka：“室内布线的带电电线绝缘诊断设备的开发”日本电气工程师学会学报 122・6（2002 年）。

千葉, 伊坂: "電界中に直立する非接地人体モデルの短絡電流特性"電気学会論文誌. 120. 1-7 (2000)

Chiba, Isaka：“电场中直立的不接地人体模型的短路电流特性”，日本电气工程师学会会刊 120. 1-7 (2000)。

千葉, 伊坂: "電界中の絶縁性円板上に直立する人体内電流密度"電気学会論文誌. 120. 630-636 (2000)

Chiba, Isaka：“人体在电场中直立在绝缘盘上的电流密度”，日本电气工程师学会汇刊 120. 630-636 (2000)。

T. Matsumoto, N. Hayashi and K. Isaka: "Analysis of induced current density in spherical human model under UHV power line"Journal of Institute of Electrical Installation Engineers of Japan. 21, No.4. (2001)

T. Matsumoto、N. Hayashi 和 K. Isaka：“特高压电力线下球形人体模型感应电流密度分析”日本电气安装工程师学会会刊。