1. Select one piece of glass lid for test.

2. Put Transparent Tape on the glass lid surface, in case of hurting people during testing.

3. To wipe the inside surface of the glass lid 15 times with sandpaper 120#, and check no crack is OK.

4. Then put the glass lid on the test platform with inside downward for 24 hours.

5. Check the glass lid, no creaks or cracks is good.

6. Record the test results.

7. Randomly drawing 3 glass lid samples to test, the batch will not pass if one of the three fails the test.