Procedure Title: Grain Volume
Instrumentation: Helium Porosimeter
Theory of Operation:
• The Helium Porosimeter is used to determine grain volume (solid volume) of a core sample. The principle is based on Boyle-Mariotte’s law.
• Boyle-Mariotte’s Law is used to calculate grain and pore volume from two measures of pressure of a known mass of helium (or nitrogen). The gas is initially held in a reference tank at a reference pressure and then expanded in into a matrix cup (core holder).
Analytical Procedure:
Create an EXCEL report template to make the calculations for the grain volume.
Insert the sample data into the EXCEL report (sample characteristics, date and time of test, operator, atmospheric pressure (Patm) read).
Load the sample and the suitable billets.
Build-up the pressure to the reference pressure (Pref) then wait for pressure stabilization.
Input reference pressure (Pref) read in the EXCEL report.
Expand the gas into the sample, then wait for pressure stabilization.
Input the expanded pressure (Pexp) into the EXCEL report.
Results of the grain volume and pore volume are automatically available in the EXCEL report as soon as all data are input.