The tilt sensor on the Edge has an accuracy of 0.3 degrees. Acting as a bubble level, it is a general indicator of perpendicularity to an imaginary line related to the center of the earth. The readings inform you how well the Edge sits on a flat surface and whether your base is moving or not when you actuate the joints. Being off-level may cause the Edge to sit unnaturally and swing to an off-upright orientation when it is at rest. In conjunction with the Base Deflection test, the Tilt diagnostic is also a good indicator of the stability of the relationship between your part and the Edge.