How A Gravimeter Measures Specific Gravity
The Earth is surrounded by Gravity and that affects every aspect of our day to day life. It plays such a significant part in the science world and the understanding of how our world works, but some may wonder how is it measured?
The way to measure the gravity found on the Earth is by measuring it with an instrument called a gravimeter. A gravimeter is a type of accelerometer (a device to measure acceleration) that measures is designed to be extremely sensitive to measuring the downward acceleration caused by gravity in measurement units known as gals. The constant downward acceleration of gravity varies by about 0.5 depending on which area of the Earth you are located this fluctuation is caused by geological structures and the shape of the Earth.
There are two types of Gravimeters a relative gravimeter and an absolute gravimeter. Relative gravimeters take values of gravity in one area and compare them with another while absolute gravimeters measure the local gravity. There many different types of Gravimeters some work by measuring the acceleration of mass inside of a vacuum housed free-fall, and others measure acceleration by the amount a weight stretches a spring.
The most accurate gravimeters though house a small suspending sphere inside of a sable magnetic field. You measure the gravity based on the amount of energy needed to create a magnetic field strong enough that it can suspend the sphere inside the tube in comparison to the Earth’s gravity. This is so accurate it can calculate one nanogal which is equal to one thousandth of one billionth of the Earth’s surface gravity.
These measurements can tell us a lot about the Earth’s gravitational pull and give us information that benefits us in many aspects of life such as in metrology and in geographical research.Want to know more? Go ahead: So what does it take to get into space anyway?