The invention discloses a precise simple-
pendulum type relative gravity meter. One
pendulum rod or two suspension fibers are connected with a cross beam, the lower portion of the
pendulum rod or the lower portions of the suspension fibers are connected with a pendulum
mass, and then a simple-
pendulum system is formed. A support supports the simple-
pendulum system through wear-resisting contacts on the cross beam. The stability of the environment where the simple-
pendulum system is located is kept through a vacuum cavity, a
temperature control system, an electrostatic shielding case and a damping base, equivalent pendulum length fluctuation is reduced, and therefore high-stability low-loss simple pendulum movement is achieved. A pair of
capacitor displacement
transducer polar plates are arranged over the pendulum
mass and a pair of
capacitor displacement
transducer polar plates are arranged under the pendulum
mass. The
capacitor displacement
transducer polar plates and the pendulum mass form a variable-area capacitor displacement transducer together, wherein the variable-area capacitor displacement transducer is used for measuring real-
time displacement of the pendulum mass. A first oscillation starting and pendulum locking displacement executing
machine and a second oscillation starting and pendulum locking displacement executing
machine are installed on the two sides of the pendulum mass respectively, and therefore an oscillation starting and pendulum
locking mechanism for simple-pendulum motion is formed. The precise simple-pendulum type relative gravity meter is simple in structure, convenient to use, beneficial to maneuvering observation and capable of achieving measurement of simple-pendulum type relative gravity on the level of the resolution of 0.1mgal.