The Penetrometer Apparatus is a laboratory tool used to measure the hardness of materials such as soil, concrete, asphalt and other materials. The device consists of a cylindrical barrel with a sliding plunger and a dial gauge. The plunger is pushed into the material and the dial gauge measures the force required to penetrate the material. The dial gauge is calibrated in kilograms per square centimeter and can be used to accurately determine the hardness of the material. The Penetrometer Apparatus is used in construction and geotechnical engineering to evaluate the load-bearing capacity of a material before it is used in a construction project.