It is a rapid method of determining the moisture content. Though less accurate, it is more suitable as a field test. The method shall not be used if the soil contains a large proportion of clay, gypsum, calcareous matter or organic matter.
Evaporating Dish– 10 to 15 cm in diameter.
Palette Knife or Steel Spatula-having a blade 10 cm long and 2 cm wide.
Balance – of sufficient sensitivity to weigh the soil samples to an accuracy of 0.4 percent of the mass of the soil taken for the test.
Clean the evaporating dish, dry and weigh (W1).
Take appropriate quantity of soil specimen in the evaporating dish and weigh (W2).
Pour methylated spirit over the soil at the rate of about one millilitre for every gram of soil taken so that the soil is well covered.
Work the methylated spirit well into the soil with the palate knife and break up any large lumps of soil.
Place the evaporating dish on a surface which will not be affected by heat and ignite the methylated spirit. Stir the soil constantly with the spatula or knife taking care to see that none of the soil is lost.
After the methylated spirit has burnt away completely, allow the dish to cool and weigh it with the contents (W3).
The percentage of water content shall be calculated as follows: