Schmidt Concrete Test Hammers by Proceq are the original brand of rebound hammers for non-destructive testing of hardened concrete by the rebound method. Schmidt Hammers are sometimes referred to as Swiss hammers. A plunger rod is pressed against the concrete surface until a spring-loaded mass releases, causing an impact. The degree that the mass bounces back is registered as the "rebound number" and used to evaluate the hardness properties of the concrete. Simple operation and portability make the concrete test hammer a good choice for rapid assessments of hardened concrete.
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There are two types of concrete rebound test hammers based on the impact energy they produce. Both types are effective on concrete mixes with a similar range of compressive strengths.
Type N hammers have a higher energy output to test a wide range of concrete structures. They are often considered as “standard” models and used when testing concrete elements 4in (100mm) or more in thickness.
Type L hammers test concrete with similar compressive strength ranges but generate lower impact energy and provide more repeatable values when testing green concrete or areas less than 4in (100mm) thick. They are Ideal for precast pipe or checking early-age concrete for form removal or post-tensioning operations. Type L hammers also reduce cosmetic and structural damage to concrete with thin cross-sections.
Schmidt concrete hammers are available in various model types including the Original Schmidt Hammer, Silver Schmidt, Schmidt Live, and Rock Rebound Test Hammers. Models are available in simple analog versions or with electronic measurement systems and data management features.