1. Stress line identification method: Using a strengthened glass identification instrument to detect the stress lines on the surface of the glass, this method can most easily identify whether the glass has undergone tempering treatment.
2. Stress spot identification method: When tempered glass is cooled by wind, the wind pressure on the glass surface cannot reach absolute uniformity, which can cause birefringence of light. When observed from a distance of one meter at a 56 degree angle, the tempered glass surface will have different areas of color and brightness changes.
3. Fragmentation state identification method: After shattering the glass, if there are no obvious sharp angles and it is in the state of blunt angle small particles, it is considered as tempered glass.