Search results
Results From The WOW.Com Content Network
However, absolute instruments are somewhat larger and significantly more expensive than relative spring gravimeters and are thus relatively rare. Relative gravimeter usually refer to comparisons of gravity from one place to another. They are designed to subtract the average vertical gravity automatically.
This page was last edited on 12 December 2019, at 00:40 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
From Wikipedia, the free encyclopedia. Redirect page
Gravimeter with variant of Repsold pendulum The large increase in gravity measurement accuracy made possible by Kater's pendulum established gravimetry as a regular part of geodesy . To be useful, it was necessary to find the exact location (latitude and longitude) of the 'station' where a gravity measurement was taken, so pendulum measurements ...
Variations in the gravity field of the Moon, from NASA Gravity measurement devices, pendulum (left) and absolute gravimeter (right) A relative gravimeter. The reference surface (level) used to determine height differences and height reference systems is known as mean sea level.
Since this type of dropping-mass gravimeter derives its accuracy and stability from the constancy of the speed of light as well as the innate properties of helium, neon, and rubidium atoms, the 'gravity' term in the delineation of an all-electronic kilogram is also measured in terms of invariants of nature—and with very high precision.
Gravity anomalies covering the Southern Ocean are shown here in false-color relief. Amplitudes range between −30 mGal (magenta) to +30 mGal (red). This image has been normalized to remove variation due to differences in latitude.
The gravity anomaly at a location on the Earth's surface is the difference between the observed value of gravity and the value predicted by a theoretical model. If the Earth were an ideal oblate spheroid of uniform density, then the gravity measured at every point on its surface would be given precisely by a simple algebraic expression.