fig: core cutter
– In this method, a cylindrical cutter called core cutter with dolly of known dimension is used.
– A dolly is placed over the cutter and embeded to the ground to it’s full depth and is taken out carefully without disturbing the sample .
– The surplus amount of soil is trimmed out using knife or spatula.
– Water content by soil is determined using oven drying method.
– Volume of cylinderical cutter is determined from it’s known dimension.
Let us consider,
Wt. of cutter = W1
Wt. of soil sample + cutter = W2
Wt. of soil only = W2 – W1
Wt. of dry soil with cutter = W3
Water content in soil(w) = W2 – W3
weight of dry soil (W4) = W3-W1
Volume of cylindrical cutter = V
Bulk density of soil (rt) = W4/V
Dry density( rd) = rt / (1+w)
w= water content of soil determined by oven drying method.