Search results
Results from the WOW.Com Content Network
In SI units, permeability is measured in henries per meter (H/m), or equivalently in newtons per ampere squared (N/A 2). The permeability constant μ 0, also known as the magnetic constant or the permeability of free space, is the proportionality between magnetic induction and magnetizing force when forming a magnetic field in a classical vacuum.
Historically, the constant μ 0 has had different names. In the 1987 IUPAP Red book, for example, this constant was called the permeability of vacuum. [12] Another, now rather rare and obsolete, term is "magnetic permittivity of vacuum". See, for example, Servant et al. [13] Variations thereof, such as "permeability of free space", remain ...
magnetostatics (ratio of the permeability of a specific medium to free space) Relative permittivity = electrostatics (ratio of capacitance of test capacitor with dielectric material versus vacuum) Specific gravity: SG (same as Relative density) Stefan number: Ste
where μ 0 is the vacuum permeability (see table of physical constants), and (1 + χ v) is the relative permeability of the material. Thus the volume magnetic susceptibility χ v and the magnetic permeability μ are related by the following formula: = (+).
To describe a soft ferromagnetic material for technical use, the following parameters are specified: (Relative) permeability Ratio of induction B in the material caused by some field H to an induction in a vacuum in the same field; it is a dimensionless value, as it is relative to a vacuum permeability;
Permeation can occur through most materials including metals, ceramics and polymers. However, the permeability of metals is much lower than that of ceramics and polymers due to their crystal structure and porosity. Permeation is something that must be considered carefully in many polymer applications, due to their high permeability.
Vacuum: 1 (by definition) Air: 1.000 589 86 ... Toggle the table of contents. Template: Relative permittivity table. 2 languages ...
The concept of permeability is of importance in determining the flow characteristics of hydrocarbons in oil and gas reservoirs, [4] and of groundwater in aquifers. [5]For a rock to be considered as an exploitable hydrocarbon reservoir without stimulation, its permeability must be greater than approximately 100 md (depending on the nature of the hydrocarbon – gas reservoirs with lower ...