The Digi-Schmidt concrete Test hammer couples the original Schmidt hammer with rebound measuring sensors and microprocessor technology to provide an instrument designed for applications requiring numerous measurements. The method is rapid, reproducible, and has resolution previously unattainable by manual models.
The hammer is connected to a control and display unit by means of a connecting cable. Strength values are shown digitally as they are taken and also displayed as groups of bars on the 128 x 128 pixel graphic LCD. Mean value and standard deviation for a preset number of measurements are computed and displayed. Via the menu display, the user can select: hammer impact direction (up, down, horizontal, etc.); desired engineering units (psi, MPa, kg/cm2, or N/mm2), and indicate the specimen size and type (cylinders, cubes, etc.) for the strength data to be predicted.
The instrument measuring range is 1,450 to 10,150 psi (10-70 N/mm2) using 2.207 Nm impact energy. Accuracy is ±0.2R with 0.5R reproducibility. Rebound vs. strength correlation curves for 7 and 28 day strengths are installed in memory, or the users own data may be installed via keyboard entry. The Internal memory holds 5000 measurements, each with date and time. Data can be transferred via the RS-232C interface to a PC in Microsoft Excel using the included cable and software. Direct printing is possible.
The Digi-Schmidt consists of the test hammer, control and display unit, connecting cable, PC cable, carrying strap, rubbing stone, instruction manual and a plastic carrying case.