The EM39S probe provides measurement of the magnetic susceptibility of the formation in the vicinity of a borehole or monitoring well. The EM39S, with intercoil spacing of 50 cm, provides good vertical resolution while still achieving a reasonable range of investigation into the surrounding medium. High sensitivity and low noise performance characteristics ensure an excellent range of measurement for most geological applications.

The susceptibility response is unaffected by plastic casing, and unlike conventional magnetometers, is unaffected by either variations in remanent magnetization of the surrounding soil or rock, or the strength of the earth’s magnetic field.