A type of [[microresistivity log]] recorded from a tool that uses three [[button]] electrodes spaced 1 in. apart in a line, located on a [[pad]] that is pressed against the [[formation]] wall. The lower electrode is the [[A electrode|A current electrode]]. The [[potential]] of the upper electrode with respect to a remote reference electrode gives a 2 in. [[micronormal]], and the difference between the two upper electrodes gives a 1.5 in. [[microinverse]] ([[lateral device|lateral]] type) measurement. Because [[mud cake]] usually has appreciably lower [[resistivity]] than the formation, the microinverse will read less than the micronormal when mud cake is present. This difference (called [[positive separation]]) usually indicates a permeable formation. A [[caliper  log|caliper]] curve is usually recorded at the same time.

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