Electrostatic Hazards Estimation

It is not possible to assess the effect of the substrate surface independently however, the powder can be characterized with respect to effective size by means of a simple sieve analysis that can be used to get a cumulative size distribution. If the total fraction that passes each size sieve is plotted against the sieve opening on normal probability paper, the mean weight-diameter from the 50% point is obtained and the standard deviation from the sizes corresponding to the 13% and/or 83% diameter. The effective (surface mean) particle diameter can then be calculated by means of the equation given by Orr and Dallavalle [66]  

Except for Pollock et al., none of the other investigators provided size data  

The principal property determining the relative importance of contact and induction is the conductivity due to the combined conduction of the surface and bulk. It is inferred from the foregoing and from the work of Cleves et al. that electrification by contact is reduced, while induction is increased, with increasing humidity and temperature. 

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