Dictionary:Metal factor (MF)
A measure of the total frequency-dependent change in conductivity or capacitivity of a rock, used in the interpretatation of IP data. Metal factor is the percent-frequency-effect (q.v.) normalized by dividing by the measured resistivity (ρα in ohm-feet) and multiplied by a constant:
1. Originally metal factor was defined as
where ρdc is the low-frequency resistivity and ρac is the high-frequency resistivity in ohm-feet.
2. In the frequency domain the definition used is
3. In the time domain, the metal factor is
where M is chargeability in millivolt-seconds per volt and ρdc is in ohm-meters. This unit is similar to Keller’s parameter, specific capacity (q.v.) or static capacity.
The metal factor has units of conductivity. It is also called metallic-conduction factor.