An analysis of charged floor potential using electromagnetic field theory

The transient electromagnetic wave generated by electrostatic discharge (ESD) has a spectrum of wide frequency range and causes unpredictable errors in the operation of highly technical electronic apparatus, posing serious problems in our high information society. The charging of a walking body is assumed to be one main cause of ESD, and the use of a floor material of low electric resistance is recommended, but its effects are not as yet clearly understood. We have proposed a model of the mechanism of decay of charged potential of the human body on the flooring materials, and the validity of the model has been proved experimentally. But in the theory, the electrostatic capacity is introduced a priori between the flooring materials and iron reinforcing bar that is the reference of an electric potential. The electrostatic capacity is the quantity defined by the potential and electric charge of the conductor and not defined between the insulators, such as flooring material and conductors. On the other hand, in his book Murasaki insists on the necessity of the electrostatic capacity between the charged insulator and conductor as an “imaginary quantity” for understanding electrostatic damage, but this is not supported by electromagnetic theory. In this paper, the coincidence of the former result from electric circuit analysis and our new result from electromagnetic field theoretic analysis supports the correctness of the “imaginary quantity” of the electrostatic capacity to the flooring materials.