Casagrande's Apparatus

This equipment is used to determine the Liquid Limit of a soil sample. The liquid limit is the moisture content at which the groove, formed by a standard tool into the sample of soil taken in the standard cup, closes for 10 mm on being given 25 blows in a standard manner. At this limit the soil possess low shear strength.
Liquid limit is significant to know the stress history and general properties of the soil met with construction.