Micromeritics 1305 Operator's Manual page 9

Model 1305 MultiVolume Pycnometer
Equipment Description
The MultiVolume Pycnometer 1305 accomplishes the measurement of skeletal vol-
umes by observing the reduction of gas capacity in the sample chamber caused
by the presence of the sample. Since helium or most other suitable gases pene-
trate even the smallest pores and surface irregularities, the volume obtained per-
mits computation of the ultimate theoretical density of the solid comprising the
sample if there are no closed pores.
The sample chamber with the sample present is first charged to a gas pressure of
about 20 psig (unit of measure for the Model 1305). Subsequent expansion of
this gas charge into a second precisely measured volume which previously was at
the same temperature and at zero psig results in a second pressure which be-
comes progressively smaller for larger samples. Application of mass balance equa-
tions for the gas permits easy computation of the sample volume when the
volumes of the empty sample chamber and the expansion chamber are known
and the pressure drop ratio upon expansion is known.
The MultiVolume Pycnometer 1305 differs from similar products in that three dif-
ferent size sample chamber configurations are provided, each containing an associ-
ated expansion volume sized to provide the maximum accuracy and resolution for
that range. A schematic diagram of the MultiVolume Pycnometer 1305 is shown
in Figure 1-2. Theoretical information is provided in Appendix A.
Jun 99
Figure 2-1. The Model 1305 MultiVolume Pycnometer
Equipment Description
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