| definition |
-
The gravity response system consists of a weight on the end of a
horizontal beam supported by a zero-length spring (a zero-length
spring is defined as one in which the tension is proportiona1 to
the actual length of the spring, that is, if all external forces
were removed the spring would collapse to zero length).
The gravity meter can detect very small changes in gravity by
measuring the restoring force necessary to bring the horizontal
beam to a reference position. It is important to note that the
instrument does not measure the total force of gravity, only
changes in gravity. The accuracy of the instrument is about .01
mgal, perhaps .005 if great care is exercised. The temperature
inside the instrument is carefully controlled by a heater and
thermostat, because changes in temperature affect the physical
properties of the spring.
[Summary provided by the University of Colorado]
|
