In ASTM D6226, a corrected percentage of open cells is estimated by remeasuring the volume of a cube after sectioning into eight parts. The UltraFoam and PentaFoam pycnometer programming provides a convenient way to automate this calculation. The report gives both the (uncorrected) Open Cell% and the Corrected Open Cell% values.
Cell Compressibility
These pycnometers offer a special feature that extends the range of usefulness for less rigid foams. By automatically increasing the measuring pressure stepwise, the resulting series of Compression% data provides a rational basis to determine:
(1) compression profile characteristics for quality control
(2) If there is an optimum pressure for the most accurate Open Cell% and Close Cell% readings.
Cell Fracture
In a similar way, the Foam pycnometers have an important analytical ability for rigid foams that have fragile cell walls. In this mode, each step of increasing pressure is tested to see if the pressure change caused a permanent decrease in Closed Cell%. The data series of Fracture% versus pressure thus presented provides a rational basis to determine:
(1) cell fracture profile characteristics for quality control
(2) If there is an optimum pressure for best accuracy.
Correction for Cut Cells
