Measurement of Electrostatic Dipoles and Net Charge on Particles Suspended In Air

  • Ms Payel Bagga, Chemical and Process Engineering Department,University of Canterbury,Private Bag 4800,Christchurch,New Zealand, New Zealand
  • John Abrahamson, New Zealand
  • Dr John Marshall, SETI Institute,NASA Ames Research Center,Moffet Field,CA 94035-14000,USA, United States
  • Explanations of electrostatic behaviour of particulates always invoke net electrostatic charge and in some cases induced dipoles on the particles .We show here evidence for forces acting like permanent dipoles on particles suspended in an air flow. In this study spherical dielectric particles are subjected to a non uniform electric field (around a probe) and their trajectory is followed with a multi flash high speed video camera. Techniques are described for the sampling, photography and analysis to rapidly provide distributions of net charge and dipole strength. The results support the existence of permanent dipoles on particles and indicate their significance compared with net charge at small distances.