1. n. [Formation Evaluation]

With reference to the conductivity of brines, the ionic conductivity provided by a unit ion concentration. The conductivity of the brine (C_w, in siemens per meter or S/m) is determined by the equivalent conductance, (B, in S/m per meq/cm³) and the ion concentration (N, in milli-ion equivalent, or more commonly milliequivalent, meq per cm³) as C_w = B * N.

See: cation exchange capacity,  dual water