The Rockwell hardness testing method of imported Rockwell hardness testers from Japan has become one of the commonly used hardness testing methods (alongside Brinell and Vickers hardness testing methods) due to its simple operation, rapid measurement, and convenient reading. It is widely used in many industrial fields such as mechanical manufacturing, metallurgy, chemical engineering, building materials, as well as scientific research, quality testing and other institutions, providing important basis for material performance evaluation and product quality control.

Calibration of Rockwell hardness tester imported from Japan FT:

1. Choose the appropriate standard hardness block:

-The hardness value of the standard hardness block should be close to the hardness range of the tested object, and the accuracy level of the hardness block should be higher than that of the calibrated hardness tester. For example, if the hardness of the tested object is expected to be between HRC 40 and 50, a standard hardness block with a hardness value within this range should be selected, and its accuracy level can be HRC ± 0.5 or higher.

2. Environmental condition control:

-Calibration should be carried out under stable environmental conditions, generally requiring room temperature control at (23 ± 5) ℃ and relative humidity not exceeding 70. Avoid calibration in environments with large temperature changes, vibrations, or dust to avoid affecting the accuracy of calibration results.

3. Calibration steps:

-Place the standard hardness block on the worktable of the Japanese FT imported Rockwell hardness tester, ensuring good contact between the hardness block and the worktable, without shaking or tilting.

-Adjust the height of the worktable of the hardness tester so that the indenter slowly contacts the standard hardness block until the indicator displays a certain reading. Then apply the initial test force and maintain it for the specified time, then apply the main test force and maintain it for the same period of time.

-Read the indicated value of the hardness tester and record the test results. In general, multiple tests need to be conducted on the same standard hardness block, and the average value is taken as the test result.

-Compare the test results with the nominal value of the standard hardness block and calculate the error. If the error exceeds the allowable range, it needs to be adjusted according to the user manual of the hardness tester. The methods of adjustment may include adjusting the zero point of the indicator, adjusting the magnitude of the test force, or adjusting the position of the indenter.

4. Verification after calibration:

-After completing the calibration adjustment, use the standard hardness block again for testing to verify the calibration effect. Ensure that the error between the test results and the nominal value of the standard hardness block is within the allowable range, usually requiring an error not exceeding ± 1.0 HRC (the specific allowable error can be determined according to the accuracy level and usage requirements of the hardness tester).

5. Recording and identification:

-Detailed records of the calibration process and results, including the calibration equipment used, calibration time, calibration personnel, information on standard hardness blocks, test data, and adjustments made. At the same time, attach a calibration qualification label on the hardness tester, indicating the calibration date and expiration date, etc., so that the status of the instrument can be clearly determined during subsequent use.