POROSITY

Sample Matrix:
Soil

Technique:    
Gravimetric/Volumetric

Reference Method:
Based on methods from “METHODS OF SOIL ANALYSIS – Part1 Physical and Mineralogical Methods”, AGRONOMY NO.9 PART1


Scope of Application:    
This method is only applicable to soils.  Data is reported as the fraction of the total volume occupied by pores.

Principle of Method:    
Total porosity can be calculated from the dry bulk density and the particle density of the sample. The ratio of the bulk to particle density is the fraction of the volume occupied by solids. This value subtracted from unity gives the fraction of the total volume that is occupied by pores. The bulk density is obtained by drying the soil from a known volume as it existed in-situ. The particle density is determined using the pycnometer method based on the mass and volume determined by calculation from the mass and density of fluid displaced by the sample.

Sampling:
An undisturbed core sample of greater than 75mm and preferably 100mm, if possible with the height of the cylinder not exceeding the diameter. A duplicate sample is also required for %Moisture calculation.