What is the reason for the unstable vibration of Feng Shui compass test?

Put the compass on a flat table and pay attention to the stability of the table. first

First, gently rotate the inner disk so that the cross indicator line (nylon line) on the outer disk can press the angle values of "0", "90", "180" and "270" on the inner disk. The operator's eyes point from top to bottom.

Look down carefully on the south dial to see if the "positive cross" of the compass rice noodle is parallel to the "cross indicator" of the outer dial. If it is parallel, it does not affect the actual use and does not need correction.