How does Zhongze Company ensure the accuracy of its Rockwell hardness testers?

Our company's Rockwell hardness tester is precision-designed; during use, the operator only needs to press the START button for the application and unloading of the main test force to run automatically, so as to avoid any possible errors.
When reading the hardness value, we have designed a clear dial; when using a diamond indenter for testing, read according to the bold black letters on the outer ring of the dial; when using a steel ball indenter for testing, read according to the red letters on the inner ring of the dial, which can ensure the accuracy of the reading.