What are the two main types of gravimeters?
There are two types of gravimeters: absolute and relative. Absolute gravimeters measure the local gravity in absolute units (Gal). Absolute gravimeters are compact (Autograv CG-5 model) and used in the field. They work by directly measuring the acceleration of a mass during freefall in a vacuum.
What is stable gravimeter?
An instrument that uses a high order of optical and/or mechanical magnification so that an extremely small change in the position of a weight or associated property can be accurately measured.
What instrument measures gravity?
gravimeter
gravimeter, also called gravity meter, sensitive device for measuring variations in the Earth’s gravitational field, useful in prospecting for oil and minerals. In one form, it consists of a weight suspended from a spring; variations in gravity cause variations in the extension of the spring.
How accurate is a gravimeter?
Such instruments are capable of an accuracy of about two parts per billion or 0.002 mGal and reference their measurement to atomic standards of length and time.
How does a superconducting gravimeter work?
A spherical superconducting mass is levitated using a magnetic force that exactly balances the force of gravity. The superconducting property of zero resistance allows the currents that produce the magnetic field to flow forever without resistive loss as long they are kept below a critical temperature.
What is satellite gravimetry?
Satellite Gravimetry investigates the gravity field of the Earth including its time variations, using satellite measurement methods, in particular: at present the GRACE Follow-On mission, with satellite gradiometry like the GOCE mission (2009-2013).
Is gravity measured in Newtons?
gravity force is measured in newtons (N) gravitational field strength (g) is measured in newtons per kilogram (N/kg)
What is the instrument used to measure Earth’s movement?
Seismographs are instruments used to record the motion of the ground during an earthquake. They are installed in the ground throughout the world and operated as part of a seismographic network.
What is precision in gravimeter?
High-precision absolute gravimetry may be defined as obtaining repeatability of individual gravity station occupations with a scatter of ±3 µGal (3×10-8ms-2 from the station mean) or better. High-precision absolute gravity values have a number of theoretical and practical applications.