Micromeritics 1305 Operator's Manual page 25

Model 1305 MultiVolume Pycnometer
FILL RATE
control valve
VENT RATE
control valve
PREP/TEST valve
Jun 99
Controls the rate of pressure build when charging the
sample chamber or the flow rate when purging a sam-
ple during preparation. A judicious balance of the ap-
plied pressure (say, 22 psig) along with this setting
permits nearly the same charging pressure to be
reached during test, ensuring maximum reproducibil-
ity. Turn the valve clockwise to reduce the flow rate;
counterclockwise to increase it. A stop will be
reached just before flow entirely ceases.
Controls the rate of flow when the VENT valve is
suddenly opened, especially if a vacuum is applied to
the discharge port. Proper setting of this control pre-
vents fine powders from being pulled from the sam-
ple cup and deposited in the valves and tubing of the
instrument.
Always begin with this control fully clockwise if fine
powders are to be measured.
Divides the instrument's internal volume into two
parts: the sample cell volume and the expansion vol-
ume. These two volumes are isolated and the expan-
sion volume is sealed when the valve is in the PREP
position. The sample cell may then be charged with
gas under pressure without altering the pressure in the
expansion volume.
When placed in the TEST position, the expansion vol-
ume is connected to the sample chamber volume and
a continuous flow-through path is established to per-
mit purging. The resulting pressure then depends upon
the volume ratios and initial pressures in the spaces.
Controls and Components
3-3