ABSTRACT
This chapter discusses the specific resistance, dielectric constant, specific charge, and contact potential difference of particles. These electrical properties are necessary for studying the behavior of electrically charged particles, electrostatic precipitation, electrostatic powder coating, electrostatic powder imaging, and so on. The electric resistance of a powder bed is one of the most important properties, especially in relation to electrostatic precipitation. The specific resistance usually decreases with the packing density of the powder bed. The dielectric constant of particles is necessary to estimate the dielectrophoretic force or the maximum charge attainable by field charging. The apparent dielectric constant depends on the packing fraction, temperature, and humidity, as in the case of the specific resistance. The specific charge is sometimes approximated by the total charge of powder divided by the mass of the powder. The contact potential difference of particles is essential for the estimation of the charge polarities and the amount of the charge acquired in various powder handling processes.
