Micromeritics FlowSorb III 2305 Operator's Manual page 42

Preparing the FlowSorb for Operation
5. Open the Toggle Switch on the lower right side of the FlowSorb to admit gas.
Toggle Switch
6. Using the Flow Adjustment Valve Knob, adjust the flow until the float is
centered on or near the calibration mark on the flowmeter tube. If you are
unable to accomplish this, the gas supply pressure is maladjusted. Readjust
the supply pressure to approximately 0.11 MPa (15 psig) (refer to Gas
Supply in Chapter 1).
Note that the Flow Adjustment Valve Knob should not be used to stop the gas
flow. Only the Toggle Switch should be used.
7. Install a Dewar about the U-tube on the Cold Trap, orienting it such that
the split insulating stopper can be put in place.
8. Place the rear half of the stopper on top of the Dewar.
9. Pour liquid nitrogen into the Dewar through the open front space until the
liquid is within a centimeter (0.5 in.) of the lower stopper surface.
10. Place the front half of the Dewar stopper on top of the Dewar.
11. Turn the Path knob to the desired position to begin the purging process.
•
Short requires 5 to 10 minutes
•
Long requires 20 to 25 minutes
Both paths should be purged.
12. After the required purging time, turn on the power switch located on the
lower right side of the instrument. Allow an additional 30 minutes of purg-
ing for complete temperature equilibration and operational stability.
Sample preparation should be begun immediately so that it will be proceeding as
equilibration is achieved. Adsorption measurements, likewise, need not be delayed.
3-2
Flowmeter
FlowSorb III
To Gas Source
Flow Adjustment Valve Knob
Mar 2012