Magnetometers are distinct from metal detectors, which detect metallic objects by detecting their conductivity.

Magnetometers can detect only magnetic ( ferrous ) metals, but can detect such metals at a much larger depth than a metal detector ; magnetometers are capable of detecting large objects, such as cars, at tens of meters, while a metal detector's range is rarely more than 2 meters.

Magnetometers used in the Earth sciences are called geophysical surveys, a term that also embraces a wide range of other geophysical techniques including gravity, seismic refraction, seismic reflection, electromagnetics ( EM ), induced polarisation ( IP ), magneto-tellurics ( MT ), controlled source magneto-tellurics ( CSAMT ), sub-audio magnetics ( SAM ), mise-a-la-masse, resistivity, self Potential ( SP ) and Very Low Frequency ( VLF ).

Magnetometers are also used to detect archaeological sites, shipwrecks and other buried or submerged objects.

Magnetometers are used in directional drilling for oil or gas to detect the azimuth of the drilling tools near the drill.

Magnetometers such as the German Forster are used to locate ferrous ordnance.

Magnetometers are also a component instrument on the Mercury MESSENGER mission.

Magnetometers can also be classified as " AC " if they measure fields that vary relatively rapidly in time, and " DC " if they measure fields that vary only slowly ( quasi-static ) or are static.

Magnetometers react very strongly to iron and steel, brick, burned soil, and many types of rock, and archaeological features composed of these materials are very detectable.

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 ).

Magnetometers can also locate zones ignited by lightning ) and map siderite ( an impurity in coal ).

Magnetometers have a very diverse range of applications, including locating objects such as submarines, sunken ships, hazards for tunnel boring machines, hazards in coal mines, unexploded ordnance, toxic waste drums, as well as a wide range of mineral deposits and geological structures.

Magnetometers assist mineral explorers both directly ( i. e. gold mineralisation associated with magnetite, diamonds in kimberlite pipes ) and, more commonly, indirectly, such as by mapping geological structures conducive to mineralisation ( i. e. shear zones and alteration haloes around granites ).

Magnetometers detect minute deviations in the Earth's magnetic field caused by iron artifacts, kilns, some types of stone structures, and even ditches and middens in archaeological geophysics.

Magnetometers measure minute differences in the magnetic field of the earth caused by ferrous concentrations ( and iron objects ) in the soil, thermo-remnant magnetism of fired clays, and differences in the magnetic susceptibility of disturbed soils.

Magnetometers can measure the magnetic fields of planets.

Magnetometers can give an indication of auroral activity before the light from the aurora becomes visible.

Airborne Magnetometers detect the change in the earth's magnetic field using sensors attached to the aircraft in the form of a " stinger " or by towing a magnetometer on the end of a cable.

Magnetometers monitor the auroral zone as well as the equatorial region.

* Magnetometers, usually of the flux gate type.

Magnetometers may also use a variety of different sensor types.

And, as a matter of fact, Nicolas had slept in the park only part of one night, when he discovered that Munich's early mornings even in summer are laden with dew.

But in our case -- and neither my wife nor I have extreme views on integration, nor are we given to emotional outbursts -- the situation has ruined one or two valued friendships and come close to wrecking several more.

It is one of the ironic quirks of history that the viability and usefulness of nationalism and the territorial state are rapidly dissipating at precisely the time that the nation-state attained its highest number ( approximately 100 ).

Accidental war is so sensitive a subject that most of the people who could become directly involved in one are told just enough so they can perform their portions of incredibly complex tasks.

Only one rule prevailed in my conversations with these men: The more highly placed they are -- that is, the more they know -- the more concerned they have become.

( There are two receivers in case one should be dropped and damaged.

Now we must become vague, for we are approaching one of the nation's most guarded secrets.

They are mere fragments, just one portion of preprepared messages.

The one apparent connection between the two is a score of buildings which somehow or other have survived and which naturally enough are called `` historical monuments ''.

Often it is recognized that all the details of the pattern may not be essential to the outcome but, because the pattern was empirically determined and not developed through theoretical understanding, one is never quite certain which behavior elements are effective, and the whole pattern becomes ritualized.

Two thieves are crucified with Christ, one saved and the other damned.

Again, the sufferings and disasters produced by any transgression against the commandment not to love are almost invariably associated in one way or another with childhood, with the figure of a child.

In a certain perfectly definite way, the method and the theme of his stories are one and the same.

He is a widower, his three children are dead, he has no one left on earth ; ;

Whatever pole of this contrast one emphasizes and whatever the tension between these two approaches to understanding the artistic imagination, it will be readily seen that they are not mutually exclusive, that they belong together.

they are fields of force exerting a unique influence on the sensibilities and a unique relatedness to one another.

In its place is a passionate consciousness grasped and molded to feelings of positive or negative values even as the actions of one's life are determined by constellations of process in which one is caught.

The party is usually in a room small enough so that all guests are within sight and hearing of one another.

For the occasion on which everyone already knows everyone else and the host wishes them to meet one or a few honored newcomers, then the `` open house '' system is advantageous because the honored guests are fixed connective points and the drifting guests make and break connections at the door.

The networks for military communications are one of the best examples of networks which not only must be changed with the changes in objectives but also must be changed with the addition of new machines of war.

These assumptions lead to an organization with one man at the top, six directly under him, six under each of these, and so on until there are six levels of personnel.

What I want to point out here is that all of them are ex-liberals, or modified liberals, with perhaps one exception.

The men who speculate on these institutions have, for the most part, come to at least one common conclusion: that many of the great enterprises and associations around which our democracy is formed are in themselves autocratic in nature, and possessed of power which can be used to frustrate the citizen who is trying to assert his individuality in the modern world ''.

They tell us, sir, that we are free, because we have in one hand a ballot, and in the other a stock certificate.

The continuities, contrasts, and similarities discernible when past and present are surveyed together are inexhaustible and the one is often understood through the other.