Experimental analysis of the human perception threshold of an ELF electric field

For the study of biological effects of ELF electric fields, a fundamental study has been conducted on a human perception threshold of electric field. The perception threshold was measured with human subjects and the results were analyzed. It was made clear that the field perception was based on the movement of the hair and not on other sensations. The variance in the perception threshold and its cause were investigated. The perception threshold decreased by almost 30% as the relative humidity increased from 50% to 90%. The perception threshold was also dependent on the physical condition (length and density) of the hair and psychological condition of the subject. The dependence on them was much smaller than that on the relative humidity. The cause of the gender difference of the threshold is ascribed to the difference in the physical condition of the hair. Through this study, some factors to be taken into account for the safety standard were made clear.