Search results
Results from the WOW.Com Content Network
Magnetometers used in geophysical survey may use a single sensor to measure the total magnetic field strength, or may use two (sometimes more) spatially separated sensors to measure the gradient of the magnetic field (the difference between the sensors). In most archaeological applications the latter (gradiometer) configuration is preferred ...
An aeromagnetic survey is a common type of geophysical survey carried out using a magnetometer aboard or towed behind an aircraft. The principle is similar to a magnetic survey carried out with a hand-held magnetometer, but allows much larger areas of the Earth's surface to be covered quickly for regional reconnaissance.
The term typically refers to magnetometers used by military forces to detect submarines (a mass of ferromagnetic material creates a detectable disturbance in the magnetic field). Military MAD equipment is a descendant of geomagnetic survey or aeromagnetic survey instruments used to search for minerals by detecting their disturbance of the ...
The compass is a simple type of magnetometer. Coast and Geodetic Survey Magnetometer No. 18. The compass, consisting of a magnetized needle whose orientation changes in response to the ambient magnetic field, is a simple type of magnetometer, one that measures the direction of the field. The oscillation frequency of a magnetized needle is ...
It is used in most ground surveys except for boreholes and high-resolution gradiometer surveys. [ 2 ] : 163–165 [ 3 ] : 77–78 Optically pumped magnetometers , which use alkali gases (most commonly rubidium and caesium ) have high sample rates and sensitivities of 0.001 nT or less, but are more expensive than the other types of magnetometers.
A vibrating sample magnetometer, a widely used tool for measuring magnetic hysteresis. Rock magnetism is the study of the magnetic properties of rocks, sediments and soils. The field arose out of the need in paleomagnetism to understand how rocks record the Earth's magnetic field.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate; Pages for logged out editors learn more
In 1958 Glenn A. Black and Eli Lilly, following the work of Martin Aitken and his associates at the Oxford University (UK) Archaeometric Laboratory, used proton magnetometers to locate and map buried archaeological features, including iron objects in the soil, thermoremanent magnetization of fired clays, and differences in the magnetic susceptibility of disturbed soils.