A new one-step technique to measure the effect of humidity on powder resistivity has been previously presented. In this technique, humidity of surrounding air is rapidly changed either from low to high or from high to low. Resistivity is measured simultaneously with the diffusion of water molecules. System consists of an electrode arrangement which gen-erates a uniform electric field in front of the counter electrode regardless of moisture gradient. In this presentation, we provide more experimental data obtained with five different powders, two lactoses, monoammonium phosphate, sodium chloride and common sugar. One-step measurements and traditional multi-step measurements have been performed. Also, additional measurements have been performed using standard resistivity cell. Results are compared and it can be concluded that the new technique provides meaningful results although significant hysteresis was observed during humidification and drying cycles. Finally, charging of the powder was also measured and it was noticed that it decreases with decreasing resistivity and increasing humidity.