|
| |
- For
rock or earth material, ability to transmit
fluids. Permeability equal to velocity of flow divided by
hydraulic gradient.
Source: Leet, L. Don. 1982.
Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall
- a. The permeability (or perviousness) of rock is its capacity for
transmitting a fluid. Degree of permeability depends upon the size and
shape of the pores, the size and shape of their interconnections, and the
extent of the latter. It is measured by the rate at which a fluid of
standard viscosity can move a given distance through a given interval of
time. The unit of permeability is the darcy. See also:
millidarcy;
coefficient of permeability. AGI
b. In geophysics, the ratio of the magnetic induction to the magnetic
intensity in the same region. In paramagnetic matter, the permeability is
nearly independent of the magnetic intensity; in a vacuum, it is strictly
so. But in ferromagnetic matter, the relationship is definite only under
fully specified conditions. AGI
c. See: coefficient of permeability
d. In magnetism, a general term used to express various relationships
between magnetic induction and magnetizing forces. These relationships are
either absolute permeability, which is the quotient of a change in
magnetic induction divided by the corresponding change in magnetizing
force, or specific (relative) permeability, the ratio of the absolute
permeability to the permeability of free space. ASM, 1
e. In founding, the characteristics of molding materials which permit
gases to pass through them. Permeability number is deteremined by a
standard test. ASM, 1
f. In powder metallurgy, a property measured as the rate of passage under
specified conditions of a liquid or gas through a compact. ASM, 1
Source:
Dictionary of Mining, Mineral, and Related Terms
| |
|
