The HT 225A Concrete Test Hammer is designed specifically for the non-destructive testing of concrete structures. This testing method has considerable advantages over conventional methods of assessing the compressive strength of concrete, in that large areas can be tested in a very short time, at a very low cost.  In addition, it is possible to determine the variation in concrete quality between different sections of a structure with ease. The HT 225A is comparable with the Schmidt Hammer, Type N.  This method of testing is covered by DIN 1048 and BS 1881 part 202. These standards refer to assessment of the rebound hardness of mortar which is directly related to the compressive strengths of the material being tested.

Testing Principle
The device is loaded by gently pressing the tip of the impact plunger against a solid surface, it then slides out of the housing until it is fully extended. The plunger is then pressed against the surface to be tested, this fires a percussion weight against the rear of the plunger and rebounds.

The rebound is dependent upon the hardness of the surface under test, the harder the surface the higher the rebound and vice versa. The maximum height of rebound is recorded on a scale which represents the rebound as a percentage of the forward movement of the percussion weight. The rebound number obtained with the HT 225A can be converted to a compressive strength value via conversion tables contained in the user manual. The conversion varies with the angle of test, therefore values must be corrected for those other than the standard horizontal direction. The various angular corrections are also shown in a table in the user manual.

The HT 225A Concrete Hardness Tester / Concrete Compression Test Hammer (Schmidt equivalent) can be used in accordance with:

• • ISO 8045
  • ASTM C805
  • EN 12504-2
  • BS 1881:202
  • DIN 1048
  • NFP18-417
  • UNI 9189

HT 225A Concrete Hardness Tester – Specifications

HT 225A Concrete Hardness Tester / Concrete Compression Test Hammer (Schmidt equivalent) Packing List:

• • • HT225A Unit
    • Carborundum Stone
    • Operating Instructions including Conversion Tables
    • Protective Wooden Box

HT 225A Concrete Hardness Tester (Schmidt equivalent) – Data Sheet

HT 225A Concrete Compression Test Hammer Concrete Hardness Tester (Schmidt equivalent) Data Sheet

HT 225A Concrete Hardness Tester (Schmidt equivalent) – Standards

The HT 225A Concrete Compression Test Hammer / Concrete Hardness Tester (Schmidt equivalent) can be used in accordance with the following Standards:

• ISO 8045
• ASTM C805
• EN 12504-2
• BS 1881:202
• DIN 1048
• NFP18-417
• UNI 9189

HT 225A Concrete Hardness Tester – Instruction Manual

HT 225A Concrete Compression Test Hammer Concrete Hardness Tester Instruction Manual