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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. 

Before the Hammer can be used for testing, the piston must be released out of 

the hammer into the testing position. Typically during storage and transporta-

tion, the Hammer piston will be locked inside the Rebound Hammer and will 

need to be released from the storage position. If the piston is not extended into 

the test position, place the end of the piston against a stiff surface and gently 

press the Rebound Hammer firmly against the surface. You will hear a click, and 

the piston will extend into the test position.

Figure 2: Always hold the Rebound Hammer with both hands  

perpendicular to the surface

Figure 1: The Concrete Rebound Hammer

Summary of Contents for H-2987H

Page 1: ...product manual 11 16 H 2987H Concrete Rebound Hammer ...

Page 2: ... testing position Typically during storage and transporta tion the Hammer piston will be locked inside the Rebound Hammer and will need to be released from the storage position If the piston is not extended into the test position place the end of the piston against a stiff surface and gently press the Rebound Hammer firmly against the surface You will hear a click and the piston will extend into t...

Page 3: ...desired once you get a reading you may press the button on the handle to lock the piston in place This makes your test results easier to read as it will also lock the indicator Do not touch the button until you get a reading To release the piston again for the next test press against a hard surface When you are finished using the Rebound Hammer lock the piston inside the Rebound Hammer for storage...

Page 4: ...a wall forward You will need to consider gravity when estimating the compressive strength of concrete The rebound number found when pressing up against a ceiling will differ from the number that appears if you are pressing down against a floor Please review the strike angles A B and C and the correlation curves in Reading your Results below Specialty Concrete The Rebound Hammer is designed to esti...

Page 5: ...e concrete Compare your average rebound number to the chart shown on your Concrete Rebound Hammer Consider the diagram shown here 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 usi...

Page 6: ...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 You should also verify the readings if you have reason to suspect that your Rebound Hammer is giving...

Page 7: ... Guide Bar H 2975 7 8 Guide Disk H 2975 8 9 Cap H 2975 9 10 Two part Ring H 2975 10 11 Rear Cover H 2975 11 12 Compression Spring H 2975 12 13 Pawl H 2975 13 14 Hammer Mass H 2975 14 15 Retaining Spring H 2975 15 16 Impact Spring H 2975 16 17 Guide Sleeve H 2975 17 18 Felt Washer H 2975 18 19 Plexiglass Window H 2975 19 20 Trip Screw H 2975 20 21 Lock Nut H 2975 21 22 Pin H 2975 22 23 Pawl Spring ...

Page 8: ...r 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 shall not be responsible under this warranty if the goods have been improperly maintained installed operated or the goods have been altered or modified so as to adversely affect the operation use...

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