What is Yang Gong's dragon ruler, and how to use it correctly, so as to find something for dragons.

Yang Gong's principle of using the dragon ruler: people can't sense the magnetic field themselves, but with the help of the dragon ruler as a bridge, they can interact with the natural magnetic field. A simple understanding can be said that the dragon ruler is the medium of communication between man and nature, and so is the environmental awareness of avoiding evil spirits and making money in Feng Shui. For a simple example, people can see seven main colors in the light combination, others such as infrared rays and ultraviolet rays can't be seen, and people can hear sound waves. Radio waves exist, not superstition. Therefore, things that are invisible and intangible do not exist. I wonder how many other radiation waves and electromagnetic waves there are. With the development of modern science and technology, many things and energy that people didn't understand in the past can be materialized in front of us, and so can the dragon finder. It can reflect things that people can't perceive in the swing and rotation of the probe, and people can find out the correct information and signals from it.