The invention belongs to the technical field of
gravity gradient measurement, and particularly discloses a gravity floating differential type vertical gravity
gradiometer. The gravity
gradiometer comprises a liquid container, a floater, a connecting bracket, a counter weight and a measuring
system, the floater comprises a rod part of which the upper part is partially immersed and is similar to a
buoy and a body part of which the lower part is completely immersed; the floater is arranged in the liquid container, one end of the connecting support is perpendicularly and fixedly connected to the upper surface of the rod part, the other end of the connecting support is rigidly connected with the balance weight, and the
mass center of the floater and the
mass center of the balance weight are located on the same plumb line. The bottom end of the liquid container is fixed, liquid with the density larger than that of the floater is contained in the liquid container, the body portion of the floater suspends in the liquid, the
lower half portion of the rod portion of the floater is immersed in the liquid, and the upper half portion is exposed out of the liquid level. And the measuring
system measures vertical
gravity gradient change information after the gravity
gradiometer moves from the first measuring position to the second measuring position. According to the invention, high-precision measurement can be ensured, the portability of the instrument is greatly improved, and the
measurement cost is reduced.