Electrical conductivity

     From Wikipedia, the free encyclopedia.

Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. Conductance is an electrical phenomenon where a material contains movable particles with electric charge, which can carry electricity. When a difference of electrical potential is placed across a conductor, its movable charges flow, and an electric current appears.

A conductor such as a metal has high conductivity, and an insulator like glass or a vacuum has low conductivity. A semiconductor has a conductivity that varies widely under different conditions, such as exposure of the material to electric fields or certain frequencies of light.

Electrical conductivity is the reciprocal of electrical resistivity (1/[ohm-cm]). Its SI derived unit is the siemens (named after Werner von Siemens) per meter (A²s³m^-3kg^-1). It is the ratio of the current density to the electric field strength. This applies also to the electrolytic conductivity of a fluid.

For a discussion of the physical origin of electrical conductivity, see electrical conduction.

For the use of conductivity measurements to record pH spectra which shows the interaction between different molecules as a function of the degree of dissociation of their functional groups, see the Research Report (PDF) "The Theoprax Method" on http://www.theoprax-research.com/theoprax.pdf or the Cordis Online Abstract on http://www.theoprax-research.com/cordisth.htm.