Power transmission line magnetic fields: a survey on 120 kV overhead power transmission lines in Malaysia

The concern on electromagnetic fields (EMF) which may has detrimental effects on human health has heightened public awareness towards the overhead power transmission lines. Frequency of the electrical power lines is typically in the range of 50/60 Hz and yet is classified as extremely low frequency (ELF). Recent studies conducted, are concentrating mainly towards the existence of electric field intensity (E-field) and magnetic flux density (B-field). In this paper, emphasis is placed on the ELF magnetic fields because this is the subject that is believe to have more effect to human health. Basic properties of power lines are described and investigated. Spot magnetic field method was used for measurement, but varieties of methods are also being described here. The data obtained here are useful in order to provide the basic understanding of magnetic fields generated by the power transmission lines.