Before testing, a calibration test of the rebound instrument must be conducted.
The quality and testing performance of the rebound instrument directly affect the accuracy of concrete strength estimation.
Only a rebound instrument with good performance can ensure the reliability of the test results.
The calibration of the rebound instrument should be carried out under dry conditions with a room temperature of 5 ℃ to 35 ℃.
It should be struck vertically three times on a standard steel anvil with a Rockwell hardness HRC of 60 ± 2, and the average calibration value should be 80 ± 2.
Otherwise, the rebound instrument must be adjusted or calibrated.
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