Micromeritics AccuPyc 1330, Руководство оператора

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ANALYSIS THEORY
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
CELL
and V
EXP
are at ambient pressure P
a
, are at ambient
temperature T
a
, and that the valve is then closed. V
CELL
is then charged to an
elevated pressure P
1
. The mass balance equation across the sample cell,
V
CELL
, is
P
1
(
V
CELL
−
V
SAMP
) =
n
c
RT
a
(1)
where
n
c
=the number of moles of gas in the sample cell,
R =the gas constant, and
T
a
=the ambient temperature.
Figure B-1. Simplified Block Diagram
The mass equation for the expansion volume is
P
a
V
EXP
=
n
E
RT
a
2)
where
n
E
= the number of moles of gas in the expansion volume.
Calibrated Expansion
Volume
V
EXP
Calibrated Sample
Cell Volume
V
CELL
V
SAMP
Valve
AccuPyc 1330 APPENDIX B
September 1996 B-1