1. To measure the overall bow of tempered glass, place the glass on an inspection bench. Run a stretched wire, on the two edges of the glass and fasten the wire. Raise both ends of the wire by using the feeler gauge of the same thickness. Use another feeler gauge to measure the gap between the midpoint of the glass and the stretched wire. The difference between the gap distance and the thickness of the elevating feeler gauge is the amount of deformation. Divide the amount of deformation by the length of the glass to calculate the overall bow of the tempered glass.

2. To measure the local bow of the tempered glass, place the tempered glass on an inspection bench. Press a 300 mm knife edge ruler vertically against the glass surface (about 200mm away from the edge of the glass) in a direction perpendicular to the direction of the conveyor rollers of the glass tempering furnace during glass processing. Measure the lower surface of the glass while it is being processed. Use the feeler gauge to measure the gap between the glass surface and the knife edge ruler.

3. To measure the edge kink, place the tempered glass flat on an inspection bench. Press a 300 mm knife edge ruler vertically against the surface of the glass edge ((parallel to the edge within a distance of 200mm from the edge of the glass )in a direction perpendicular to the direction of the tempering furnace rollers during glass processing. Measure the lower surface of the glass while it is being processed. Use the feeler gauge to measure the gap between the glass and the knife edge ruler (measure the amount of deformation within about 200mm along the edge of the glass).