Gravity Gradiometer, Horizontal

an instrument for gravimetric surveying that measures only the horizontal components of the gravity gradient (without measuring the curvature of the surface). It can be made from a torsion balance if the balance’s torsion system can be set for measurement in four azimuths separated from each other by 90°.

Horizontal gravity gradiometers made in the USSR are distinguished by the short arm of the balance beam of the torsion system, which ensures a short period of natural oscillations and. in the presence of a strong buffer action, rapid damping to a position of equilibrium. For dependability and speed of measurement the instrument has four torsion systems and visual recording. As a result it is four to 11 times more efficient than a torsion balance.