Related topics: magnetic field

Sensitive instruments to explore metal-rich asteroid

At the very center of the Earth is a core of metal—so hot and so deep down as to be unreachable and impossible to study directly. But we might learn more about it and the cores of other Earth-like planets by studying the ...

Worldwide coordinated search for dark matter

An international team of researchers with key participation from the PRISMA+Cluster of Excellence at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM) has published for the first time comprehensive ...

Using cell phones as space weather vanes

Your smartphone may be able to sense space weather and even get a little disoriented by it, according to researchers, who tested how geomagnetic storms affect the magnetic sensors in cell phones. The new research suggests ...

Quantum magnetometers for industrial applications

On April 1 2019, the Fraunhofer-Gesellschaft launches the lighthouse project "Quantum Magnetometry" (QMag): Freiburg's Fraunhofer institutes IAF, IPM and IWM want to transfer quantum magentometry from the field of university ...

Image: Magnetometer boom built for ESA's mission to Jupiter

A test version of the 10.5-m long magnetometer boom built for ESA's mission to Jupiter, developed by SENER in Spain, seen being tested at ESA's Test Centre in the Netherlands, its weight borne by balloons.

page 1 from 4


A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature. Some countries such as the USA, Canada and Australia classify the more sensitive magnetometers as military technology, and control their distribution.

The International System of Units unit of measure for the strength of a magnetic field is the tesla. As this is a very large unit, workers in the earth sciences commonly use the nanotesla (nT) as their working unit of measure. Engineers often measure magnetic fields in Gauss. 1 Gauss = 100,000 nT or 1 Gauss = 100,000 gamma.

The Earth's magnetic field (the magnetosphere) is a potential field. It varies both temporally and spatially for various reasons, including inhomogeneity of rocks and interaction between charged particles from the Sun and the magnetosphere.

The earth's magnetic field is relatively weak. A simple magnet that may be purchased in a hardware store produces a field many hundreds of times stronger than the earth's field. The earth's magnetic field varies from around 20,000 nT near the equator to 80,000 nT near the poles. It also varies with time. There is a daily variation of around 30 nT at mid latitudes and hundreds of nT at the poles. Geomagnetic storms can cause much larger variations.

Magnetometers, which measure magnetic fields, are distinct from metal detectors, which detect hidden metals by their conductivity. When used for detecting metals, a magnetometer can detect only magnetic (ferrous) metals, but can detect such metals buried much deeper than a metal detector. Magnetometers are capable of detecting large objects like cars at tens of meters, while a metal detector's range is unlikely to exceed 2 meters.

This text uses material from Wikipedia, licensed under CC BY-SA