1. n. [Formation Evaluation]
A log that shows the magnitude of the correction applied to the long spacing detector of a density measurement. When delta rho is above a certain value, typically ±0.15 g/cm3, the correction may no longer be accurate, and needs to be examined in more detail. Delta rho is also used as a qualitative indicator of borehole rugosity.
See related terms: azimuthal density, compensated density log, spine and ribs plot