ASTM D6726-15

1.1 This guide is focused on the general procedures necessary to conduct electromagnetic-induction, induction, electromagnetic-conductivity, or electromagnetic-resistivity logging (hereafter referred as induction logging) of boreholes, wells, access tubes, caissons, or shafts (hereafter referred as boreholes) as commonly applied to geologic, engineering, groundwater and environmental (hereafter referred as geotechnical) explorations. Induction logging for minerals or petroleum applications is excluded.

1.2 This guide defines an induction log as a record of formation electrical conductivity or resistivity with depth as measured by the induction method in a borehole.

1.3 This guide is restricted to induction measurements that are at a frequency of less than 50 KHz; are non-directional; and average formation properties around the circumference of the borehole; which are the most common induction measurement devices used in geotechnical applications.

1.4 This guide provides an overview of induction logging including (1) general procedures; (2) specific documentation; (3 ) calibration and standardization; and (4) log quality and interpretation.

1.5 To obtain additional information on induction logs see References section in this guide.