Sample Support
DIAMETER
The flexible design of the AccuPore makes it simple to
move between sample adapters. Select a sample adapter that is less than or
equal to the size of your test piece.
*Smaller sample diameters are preferred because they
reduce gas consumption.
The use of a flow restrictor plate further reduces gas consumption, and ensures the measurement is within the available range of flow rates, especially for materials with high porosity. Sample holders are available with diameters of 13 mm, 25 mm, and 47 mm. A 5 mm flow restrictor is available for the 25 mm sample holder; it reduces gas consumption by up to 18x.
MECHANICAL
SUPPORT
The sample holder must also provide sufficient
mechanical support to the test piece so it does not rupture over the full range
of pressure. For thin or weak membranes, a support with a flat surface
and small openings proves the most mechanical support.
Sample rupture can be observed by visual inspection of
the test piece when the measurement is over. Small ruptures can also be
identified in the data by step-increases of the measured flow rate in the
flow-pressure curve.
Samples with large pores, high mechanical strength, or
a propensity for re-wetting may be best analyzed on a support with larger
openings.