Nondestructive method for detecting subsurface structures, voids, discontinuities, and changes in material. gpr uses radar pulses transmitted into the ground to image the subsurface by recording electromagnetic signals reflected back to the gpr system.
Standard dimensional ratio (sdr), английский Numerical designation of a pipe series which is a convenient round number approximately equal to the ratio of the nominal outside diameter and the minimum wall thickness.
Downhole drilling assemblies, английский Mud motors and mechanical downhole motors used primarily to excavate hard soils and rock.
