Measurement of tribo and corona charging features of materials for assessment of risks from static electricity

Many of the risks from static electricity arise in relation to the maximum surface voltage that may arise when materials are rubbed. The paper describes a new approach for assessing the risks presented by static charge retained on materials by simultaneous measurements of the quantity of charge transferred, the initial peak voltage generated and the rate at which the charge can decay away. The quantity of charge transferred divided by the initial peak voltage is equivalent to a capacitance. If this ´capacitance loading´ is large then only low surface voltages will occur with practical quantities of charge transfer, and static problems are unlikely to arise from charge retained on the material itself. This approach provides a necessary addition to assessment of materials by the charge decay time when charge decay times are long