Micromeritics ASAP 2460, Operator'S Manual

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ASAP 2460 Operator’s Manual Appendix C
246-42800-01 - Aug 2013 C-15
Explanation of Terms
A pore filled with condensed liquid nitrogen has three zones:
a.) The
core
- evaporates all at once when the critical pressure for that radius is reached; the
relationship between the core radius and the critical pressure is defined by the Kelvin
equation.
b.) The
adsorbed layer
- composed of adsorbed gas that is stripped off a bit at a time with each
pressure step; the relationship between the thickness of the layer and the relative pressure is
defined by the thickness equation.
c.) The
walls of the cylindrical pore
- the diameter of the empty pore is required to determine
the pore volume and pore area. End area is neglected.
Pore
Insignificant
compared to
core length
Wall