How to checking abrasives discs planeness ???

The abrasives discs surface planeness is very important especially for the big size such like Chopsaw cutting blades - 10/12/14/16" inch. If the disc surface planeness no good, the disc will easy out of shape and even cause big vibration during workings.

This video show how to checking it and you can see from the video - Blueshark chopsaw cutting discs in good planeness condition.