Schmidt Hammer QA/QC tutorial from Techshore Inspection Service, Kochi

Schmidt hammer: Swiss hammer/rebound hammer invented by Ernst Schmidt in 1948, a Swiss engineer, is a mechanical device used to measure surface hardness and penetration resistance strength of concrete or rock.

Working Principle :
Schmidt rebound hammer works on the priciple that rebound of an elastic mass depend on the surface against which it strikes. The hammer measures the rebound of a spring-loaded and the mass impacting against the surface of the sample.
The device is allowed to hit the concrete surface with a defined energy. The rebounding of the device depends on the surface hardness and penetration resistance strength of concrete and is measured by the test equipment.
The conversion chart could be then referanced to calculate the rebound value which further can be used to calculate the compressive strength of the concrete or test specimen.