A proton magnetometer or proton precession magnetometer is a device which can measure variations in a magnetic field by detecting activity in protons. These devices are used in a number of applications on Earth and also in space exploration. Using a proton magnetometer, ferrous materials can be identified, because they influence the magnetic field around them, in turn triggering the sensitive proton magnetometer. Such devices may be connected to a magnetograph which provides a printed output of variations in the magnetic field being studied.
One application of the proton magnetometer is in archeology. Ferrous materials have been harnessed by many human societies throughout history, and sites of archaeological interest can be identified by looking for such materials. Human activities which people may not immediately associate with ferrous materials such as developing pottery glazes and farming can also generate variations in the magnetic field of the Earth which act as tell-tale signs of human activity.
These devices are also used in mineral exploration to identify sites of interest. Ferrous materials on their own can be valuable, and they can also be associated with other materials which may be of interest to a firm which engages in mineral mining activities. In this case, the proton magnetometer can be used to cut down on the guesswork involved in the exploration of a site which is believed to contain materials of interest.
Ships may be equipped with a proton magnetometer for the purpose of navigational safety, as it is possible to collide with shipwrecks and other ferrous objects and incur damage. People who are trying to locate wrecks for salvage, recreational diving, and other activities also utilize these devices in their work. The level of sophistication of the device varies, depending on the use for which it has been designed. Extremely sensitive versions can be quite costly, reflecting the more complex engineering involved in their development.
Earth isn't the only place where a proton magnetometer can be useful. Spacecraft such as probes are often equipped with proton magnetometers so that they can gather data about the planets and other formations they pass. This information can be combined with other information collected by the spacecraft to provide researchers with more information about objects in space and the history of space. The composition of soils and atmospheres is also a topic of interest among researchers who are interested in the possibility of identifying life in other corners of the universe.