Concrete Test Hammer • • • Measuring range 10 to 70 N/mm2compressive strength (below 25 N/mm2type P part number CN675 is better suited). Impact energy = 2,207 Nm. Rebound values are read from a dial. Supplied in a carrying case including a grinding stone and operating instructions. Case Dimensions: 325 x 125 x 140mm Weight: 1.6kg Test Procedure (Similar for all types) Smooth test area with a grinding stone. Perform test series of at least ten test impacts. The compressive strength of the concrete is read from a conversion chart.