Abstract
Experimental and theoretical studies were conducted on the measurement and evaluation of the contact potential difference between various powders and a metal. The apparent dielectric constant of the powder layer that appeared in theory was also measured and compared using some theoretical models. It was confirmed that the apparent contact potential difference of a polymer powder is proportional to the square of the powder-layer thickness as theoretically predicted.
The evaluation of the time-change of the contact potential difference gives the relaxation characteristics of the initial charge of the powder layer. Also, it was found that the measuring time is drastically reduced by thinning the powder layer.
The relationship between the packing fraction of the powder layer and the apparent dielectric constant was also found to be well represented by Maxwell's equation.
