Micromeritics AccuPyc 1330 Operator's Manual page 93

AccuPyc 1330
The AccuPyc 1330 Pycnometer is a gas displacement pycnometer, a type of
instrument which measures the volume of solid objects of irregular or regular
shape whether powdered or in one piece. A greatly simplified diagram of the
instrument is shown in Figure B-1.
Assume that both V
temperature T
elevated pressure P
V
CELL
where
The mass equation for the expansion volume is
where
September 1996
ANALYSIS THEORY
and V
CELL
, and that the valve is then closed. V
a
. The mass balance equation across the sample cell,
1
, is
(V − V
P
1 CELL SAMP
n =the number of moles of gas in the sample cell,
c
R =the gas constant, and
T =the ambient temperature.
a
Calibrated Sample
Cell Volume
V
CELL
V
SAMP
Figure B-1. Simplified Block Diagram
= n
P V RT
a EXP E
n = the number of moles of gas in the expansion volume.
E
are at ambient pressure P
EXP
CELL
) = n
RT
c a
Valve
a
APPENDIX B
, are at ambient
a
is then charged to an
Calibrated Expansion
Volume
V
EXP
(1)
2)
B-1