Gravimeter

A gravimeter is an instrument used to measure gravitational acceleration. Every mass has an associated gravitational potential. The gradient of this potential is a force. A gravimeter measures this gravitational force. A gravimeter is an instrument used to measure gravitational acceleration. Every mass has an associated gravitational potential. The gradient of this potential is a force. A gravimeter measures this gravitational force. The first gravimeters were vertical accelerometers, specialized for measuring the constant downward acceleration of gravity on the earth's surface. The earth's vertical gravity varies from place to place over the surface of the Earth by about ±0.5%. It varies by about ±1000 nm/s2 (nanometers per second squared) at any location because of the changing positions of the sun and moon relative to the earth.