Magnetic fields and magnetic objects have a tremendous influence on the Earth. The Aurora Borealis for example, is an interaction between solar winds and the Earth's magnetic field. A magnetometer is a sophisticated sensor that provides scientific observers with a clearer understanding of how magnetism works.
The Earth generates a magnetic field that creates measurable magnetic disturbances in the atmosphere. A magnetometer is a scientific instrument that measures this phenomenon in terms of magnetic flux density. The scientific unit for reading magnetic flux density is the Tesla or As/m2. Substances and materials that disturbs this flux are called magnetic. When magnetic materials are present, a magnetometer detects the amount of distortion these materials cause in the Earth's field. A magnetometer not only tells us how particular magnetic materials affect magnetic flux, but can also measure the strength of magnetic fields. This information can be used to discern the direction, rotation, and angle of magnetic fields, as well as the location of specific objects within it.
Magnetometers can be useful instruments in many professional applications. Light weight and portable, magnetometers are easily transported to just about any testing site. In archaeology, magnetometers can be used to find buried graves containing metallic artifacts. In military applications, magnetometers are used to locate tanks, mines, and fuel drums. The mining industry and numerous other scientific fields also measure magnetic anomalies with magnetometers.
Proton Precession Magnetometer
An inexpensive and portable magnetometer is the proton precession magnetometer. This instrument is used primarily on samples near the surface in environmental and engineering surveys. The proton precession magnetometer requires the use of a liquid rich in hydrogen atoms to produce the precession signal. For this purpose, kerosene is one of the best choices. DC currents and magnetic fields polarize the atoms and the instrument reads their precession frequency. There are limitations to this type of magnetometer, like its low level of sensitivity and high power consumption. However, it is ideal for mineral exploration and mapping underground pipelines.
Quantum magnetometers are widely used in environmental surveys, geophysical exploration, weapon detection, and other scientific applications. These instruments measure the specific magnitude of magnetic fields. Sub-atomic particles are polarized by quantum magnetometers, which causes them to process around the Earth's magnetic fields. This polarization produces a recognizable pattern that can be quantified and measured as a magnetic moment. These magnetic moments in relation to the Earth's magnetic field provide information on magnetic flux density.
In addition to having a magnitude, magnetic flux also has a direction, or vector. Vector magnetometers measure magnetic field properties traveling in a particular direction. These instruments provide a more accurate reading of magnetic flux density by eliminating cross sensitivities and operating at a very low noise level. Vector magnetometers have been utilized on spacecraft since 1988. Satellites using vector magnetometers can even measure magnetic fields of other planets and moons.