Hardness testing device PCE-HT-225A (Schmidt hammer) is a compact, mechanical testing instrument for determining concrete strength. It is a concrete testing hammer that operates based on Schmidt's measurement principle. In addition to its primary use in the construction and building sector, this easy-to-use concrete testing hammer is also employed in many other industries, such as for testing the hardness of products on rolls.

The testing is conducted with a constant test energy of 2.207 J. The initial kinetic rebound energy is indicated as a measure of concrete hardness, surface pressure, or compressive strength (kg/cm² or converted to N/mm²) on the hardness testing device. The quality of concrete is primarily assessed based on its compressive strength, as this is crucial for the load-bearing behavior and durability of concrete structures.

The compressive strength is designated by a combination of letters and numbers. For example, B 25 means it is normal concrete with a compressive strength of 25 N/mm². There are various intermediate values up to the highest strength class B 55. With the hardness testing device, you can easily, quickly, and accurately classify concrete. The concrete testing device is always delivered factory-calibrated with an order, but it can also be optionally lab-calibrated (for an additional fee) and equipped with an ISO testing certificate.