1. Turn on the oven power switch and heat to 230℃ for constant temperature.
2. Put the glass lid into the oven for 60 min.
3. Put the glass lid out of oven and throw it into the water (temperature 20℃±5℃).
4. Check the glass lid broken or not. No broken is qualified.
1. Prepare the glass lid; turn on the refrigerator power switch and adjust to 0℃±2℃.
2. Put the glass lid into the refrigerator （No overlapping）and close the door for 30 min.
3. Put water into the bucket to 2/3 of the total capacity and heat the water to 100℃.
4. Take the glass lid out of the refrigerator and put it into the 98℃±2℃ water bucket quickly.
5. Check the glass lid broken or not. No broken is qualified.