(1) The distance between the logging tool measure points for various parameters measured by a combination logging tool. Also, the correction necessary to record all parameters at the same depth reference.

(2) Pertaining to the dipmeter, it is the vertical distance in the hole between equivalent responses measured at different quadrants in the hole.

(3) Also refers to the replacement of a portion of the interstitial fluids by borehole fluids, near the borehole, during the invasion process.