Septum; Other - Micromeritics FlowSorb III 2305 Operator's Manual

Specifications
Two gas flow paths, labeled Short and Long, are provided downstream of the
sample Test position. The purpose of both is, upon removal of the liquid nitro-
gen, to delay the arrival at the detector of the nitrogen-rich gas (created by sam-
ple desorption) long enough for the flow rate to return to normal. The Short path
is usually sufficient for surface area testing. Greater surface area materials may
give up too much gas over too long a time for a short path and, therefore, the
Long path should be used.

Septum

FlowSorb calibration is accomplished by means of a septum through which
known volumes of gas are injected with a precision syringe. Any septum will
leak after some number of penetrations. The supplied syringe needles have side-
entry ports which greatly extend this life. Nevertheless, this septum will require
replacement periodically. Refer to Chapter 4 for instructions on replacing the
septum.
The knurled nut retaining the septum should be finger-tightened. Insufficient
or excessive tightening may cause septum leakage.

Other

The controls not covered here are fully described in connection with the opera-
tion or calibration procedures.
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FlowSorb III
Mar 2012