(1) A [[well log|well-log]] grid scaled in logarithmic divisions. Usually used with [[resistivity]] logs. The use of the logarithmic grid serves to enhance resolution or magnify resistivity [[reading|readings]] in the low-resistivity range and eliminates the need for [[back up galvanometer|back-up galvanometers]] and associated [[curve|curves]] in the high-resistivity range. Permits the use of [[overlay]] techniques in the solution of some exponential relationships.

(2) On the [[API log grid]], [[track|tracks]] 2 and 3 of the grid are divided usually into 4 logarithmic cycles and the grid lines follow logarithmic [[scale|scales]]. See [[scale]]
 for illustration.