Accumulation of static electricity is one of the most serious potential hazard factors for transport and storage of flammable insulating fluids. The electrostatic accumulations rate of fluid flow by friction against solid walls is the key issue to reveal the essential characteristics of accumulation process. A rotating disk system was designed and fabricated for simulating the electrification and measuring the instantaneous electric charge of several common insulating fluids such as transformer oil. How the velocity

temperature and viscosity of the fluid contribute to the electrification rate was experimentally investigated under different conditions for these fluids. It is found that the electrification rate is substantially proportional to the linear velocity of fluid flow. Its relationship with temperature is complicated

showing the existence of a minimum electrification rate in a certain range of temperature. And the qualitative behavior that stronger insulating fluid has greater electrification rate has been verified quantitatively.