Calculations

The empty cylinders used for core sampling should be clean. Before use, measure and record the empty mass and volume of the cylinders. For a cylinder, the volume is

where d is the inside diameter of the cylinder and h is the height of the cylinder.

During soil sampling, it is important the cores be completely filled with soil, but not extend beyond the ends of the cylinder.

Once soil core samples are obtained, place the soil-filled cylinder in a small tray of known empty mass. This tray holds the core sample during drying in an oven.

To obtain m_wet, subtract the cylinder empty mass and the container empty mass from the mass of the soil filled cylinder in the tray. Remove all the soil from the cylinder and place this soil in the tray. Dry the samples using oven or microwave methods, as described earlier.

To obtain m_dry, weigh the tray containing the soil after drying. Subtract tray mass for m_dry. Calculate gravimetric water content, θ_g, using

To obtain soil bulk density, use

Volumetric water content is calculated using