Charge neutralisation: A review—How can corona ionisers achieve zero coulomb and zero volt charge neutralisation?

Charge neutralisation using corona discharge is a technology that empirically appears to work well. However, without a proper understanding of the physics of charge neutralisation, it is impossible to properly solve problems when they occur. Unfortunately, some corona ionisers make us question whether they can effectively eliminate static charge because the ionisers themselves can cause problems. Ionisers can generate an external electric field that causes induction or polarisation in an object being neutralised, potentially leading to false overcharging. This review discusses in theory how to achieve zero coulomb and zero volt charge neutralisation, what the problems are that prevent charge neutralisation, how the problems can be solved, and what test method can be used to evaluate the accurate performance of ionisers, with a view to future improvements in ioniser technology.