A Preliminary Research on the Measurement Method of Electrical Charge on Suspended Particles at the Low Number Concentration

Abstract

Various static electricity countermeasures are taken in clean rooms� for preventing the pollution caused by particle adhesions. For working out a countermeasure�it is important to give consideration to the generation mechanism�characteristics and electrical charge of charged particles. However������������������������������������������������������������������������������������������� rooms have been established. Moreover�monodisperse and multi-charged particles are important as test particles for the basic study on their transport mechanism and deposition process. But�there are few studies on the charge control of these particles�those are relatively coarse and produced the manufacturing process. In this paper�the method for generating monodisperse and multi-charged particles is proposed�and the neutralization process of multi-���������������������������������������������������������������������������������������which can be utilized in an existing clean room�is also presented. It will be shown that the monodisperse and multi-charged particles can be produced with the proposed method�and that�by employing the DMA�multi-charged particles can be classified by their charges. The distribution of particle electrical charges after the neutralization corresponds well with that of equilibrated charges evaluated by the aerosol theory. The distributions of particle electrical charges in the atmosphere are also shown�that are measured with the presented system.