2.
Using the Humboldt Concrete Rebound Hammer Always hold the Concrete Rebound Hammer in both hands while in use. Also, when in use, keep the hammer perpendicular to the surface you are testing with the scale pointing up, making it easier to read. Figure 1: The Concrete Rebound Hammer Before the Hammer can be used for testing, the piston must be released out of the hammer into the testing position.
Figure 3: Push the piston in as far as it will go As long as you hold the Rebound Hammer firmly against the concrete, the rebound number will remain on the scale. Record your reading. When you pull the nnmm hammer away and allow the piston to re-extend, the scale will return to zero. The Rebound Hammer is now ready for another test. If desired, once you get a reading, you may press the button on the handle to lock the piston in place.
rebound numbers that are lower than they should be. Using the Rebound Hammer on new concrete may damage it if the strength is less than 1,000 PSI. If you are testing concrete with a lot of surface carbonation, the rebound readings will be significantly higher than normal. The thicker the layer of carbonated concrete, the higher the rebound numbers.
Figure 4: Concrete Rebound Hammer correlation curves Rebound Number Correlation curves. This diagram shows the relationship between the compressive strength for concrete, measured directly in a laboratory using concrete cylinders or concrete cubes, and the rebound numbers you receive using your Rebound Hammer. A refers to using the Rebound Hammer against a concrete floor (downward). B refers to using it against a concrete wall (forward). C refers to using it against a concrete ceiling (upward).
Note that some countries have set their own national standards for calculating test results. Therefore, follow the standards of the country where you are using your Rebound Hammer. Maintenance We recommend that you calibrate your Rebound Hammer regularly using the Humboldt Calibration Anvil, H-2972, ordered separately. For a Rebound Hammer, you should start verifying the readings after approximately 2,000 uses (or completed tests).
worn and ineffective after more than 8,000 tests. Therefore, if you have an older Rebound Hammer that is no longer providing accurate measurements, and you tried to recalibrate it but it still doesn’t work properly, send it back to Humboldt for an evaluation and/or repair.: Safety: • When using this device wear safety glasses • Do not fire the Rebound Hammer against any body part Specifications: Humboldt Concrete Rebound Hammer: H-2987 Weight: 2lbs (0.9kilograms) Size: 10.
Warranty Humboldt Mfg. Co. warrants its products to be free from defects in material or workmanship. The exclusive remedy for this warranty is Humboldt Mfg. Co., factory replacement of any part or parts of such product, for the warranty of this product please refer to Humboldt Mfg. Co. catalog on Terms and Conditions of Sale. The purchaser is responsible for the transportation charges. Humboldt Mfg. Co.
