Used to test the initial set of concrete mortar in accordance with ASTM C403. Plunger tip area is 1/20 in². Push the plunger into the mortar 1 inch periodically. Resistance in psi is indicated on the scale. Scale range is 0-700 psi. The point of initial set is reached when the penetration value is 500 psi. Penetrometer Foot is a stainless steel disk, 2.70 inch (68.58 mm) diameter.