Your welcomed, and some further info for you.
THE FUNDAMENTAL LAWS OF ELECTROSTATICS. http://www.physics.u...ces/E/E-all.pdf
http://amasci.com/emotor/voltmeas.html
http://faculty.mu.ed...5chapter 04.pdf
http://ecee.colorado...ctrostatics.pdf
MEASURING INSTRUMENTS. http://www.apcee.com...sdmeasuring.pdf
Coulomb's law. https://en.wikipedia...i/Coulomb’s_law
21.5 Coulomb’s Law http://www.mhhe.com/...u57366_ch21.pdf
Experiments and coulomb’s Law. http://www.fas.harva...s/E1b/E1b_1.pdf Page 4
Thanks again!