U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Environmental Geophysics

Electrical Conductivity and Resistivity

Electrical Conductivity (σ) and Resistivity (ρ)

Electrical conductivity is the proportionality factor relating to the current that flows in a medium to the electric force field that is applied.  It is a measure of the ability of the material to conduct an electrical current to move through the material.  Resistivity is the reciprocal of conductivity.  The units of conductivity are Siemens per meter (S/m).  The practical unit is milliSiemens per meter (mS/m).  Because Siemen, the unit of conductance, is the reciprocal of the Ohm, the unit of resistance, the units of conductivity are sometimes given as mhos/meter or millimhos/meter. .  Resistivity is the inverse of conductivity ( r = 1 / s ).  The units of resistivity are Ohm meters (Wm).


The pages found under Properties are substantially based on a report produced by the United States Department of Transportation:

Wightman, W. E., Jalinoos, F., Sirles, P., and Hanna, K. (2003). "Application of Geophysical Methods to Highway Related Problems." Federal Highway Administration, Central Federal Lands Highway Division, Lakewood, CO, Publication No. FHWA-IF-04-021, September 2003.

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