Re: Static discharge

[Bernard L Cohen <blc+@pitt.edu>]

How about an experimental approach to answering the original question. 
See how long a spark can be drawn by various activities--- this also 
depends on humidity, etc. Use this to determine the voltage. If the spark 
is 15 mm long, the voltage is 15 mm/ 0.3 mm/KV = 50 KV. This is somewhat 
typical, but higher than average for simply walking on a rug.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Mon, 11 Mar 1996, Mike McNaughton wrote:

> > Does anyone have the foggiest idea how great a static charge can be
> > developed by a person?
> This is a foggy OPINION!
> Approximate the person by a sphere of radius R and use the equation:
> V = Q / (4 pi epsilon0 R) = 9.0E9 Q / R
> This gives C = Q/V = 1.1E-10 R;  e.g. 55 pF for a radius of 0.5 m.
> Next, guesstimate the voltage from the size of the spark, see the Handbook
> of Physics and Chemistry, which says that a spark is about 0.3 mm per kV.
> Thus Q = CV = 55 nC for 1 kV
> I am curious to know what the manager is going to do with this number.
>