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The design of the saturable inductor current sensor is similar to that of a closed-loop Hall-effect current sensor; the only difference is that this method uses the saturable inductor instead of the Hall-effect sensor in the air gap. Saturable inductor current sensor is based on the detection of an inductance change. The saturable inductor is ...
Keep the temperature of the sensor wire constant and measure the voltage as a function of pressure; Note that keeping the temperature constant implies that the end losses (4.) and the thermal radiation losses (3.) are constant. [3] The electrical resistance of a wire varies with its temperature, so the resistance indicates the temperature of wire.
This is the basis of standard (pancake coil) ECT. NDT kits can be used in the eddy current testing process. [6] ECT has a very wide range of applications. Since ECT is electrical in nature, it is limited to conductive material. There are also physical limits to generating eddy currents and depth of penetration . [7]
Magnetic reconnection is a breakdown of "ideal-magnetohydrodynamics" and so of "Alfvén's theorem" (also called the "frozen-in flux theorem") which applies to large-scale regions of a highly-conducting magnetoplasma, for which the Magnetic Reynolds Number is very large: this makes the convective term in the induction equation dominate in such regions.
Researchers have developed global models using MHD to simulate phenomena within Earth's magnetosphere, such as the location of Earth's magnetopause [24] (the boundary between the Earth's magnetic field and the solar wind), the formation of the ring current, auroral electrojets, [25] and geomagnetically induced currents.
Schematic of the Birkeland or Field-Aligned Currents and the ionospheric current systems they connect to, Pedersen and Hall currents. [1]A Birkeland current (also known as field-aligned current, FAC) is a set of electrical currents that flow along geomagnetic field lines connecting the Earth's magnetosphere to the Earth's high latitude ionosphere.
In the height region between about 85 and 200 km altitude on Earth, the ionospheric plasma is electrically conducting. Atmospheric tidal winds due to differential solar heating or due to gravitational lunar forcing move the ionospheric plasma against the geomagnetic field lines thus generating electric fields and currents just like a dynamo coil moving against magnetic field lines.
The ring current system consists of a band, at a distance of 3 to 8 R E, [1] which lies in the equatorial plane and circulates clockwise around the Earth (when viewed from the north). The particles of this region produce a magnetic field in opposition to the Earth's magnetic field and so an Earthly observer would observe a decrease in the ...