1. First, select appropriate tools such as color palette, color block or gray label board according to requirements to ensure that the test environment has enough light and a relatively stable environment.

2. Secondly, put a palette or a gray standard board in the test environment to ensure that there is no dirt or spots on its surface that affect the gray level. Use test tools to record the gray values of different colors, and mark the test results at corresponding positions for subsequent analysis and processing.

3. Finally, analyze the gray scale test results to check whether there is any abnormality or problem. For abnormal results, it is necessary to adjust and deal with them in time to improve the accuracy and reliability of the test.