borehole gravity meter

1. n. [Formation Evaluation]
A logging instrument capable of making relative gravity measurements at stations along the borehole with a sensitivity and repeatability in the microGal range (about 1 part in 10-9 of the Earth's gravity field) The only commercial measurement device capable of this precision is the LaCoste & Romberg borehole gravimeter, although several research projects have been proposed to replace this classic technology.