Lu Banchi and Ding Lan ruler are collectively called Yin-Yang ruler. "Lubanchi" is a square, which is used to build a Yang door in a Yang house. The length of the ruler is one foot four inches and four-quarters of a square foot (ten inches). One foot is the key to choosing an inch in your hand. There are eight inches on it-wealth, illness, divorce, righteousness, official, robbery, harm, luck (or writing a book), wealth, righteousness, official and luck (this book) are four good, and illness and robbery are four bad. Each inch is divided into four cells, each cell has four layers of meaning, and each layer is divided into good and bad, and is marked with red and black, with red indicating good or bad. The craftsmen said it would be an honor to use the auspicious inch on this ruler as a door. This kind of ruler is also called door light ruler, or door ruler, and it is also called eight-character ruler.
Ding Lan ruler, also called Yin ruler, is one foot, one inch and eight minutes longer than the curved ruler (ten inches). It is mainly used to measure and judge good or bad luck when building tombs or placing ancestral tablets and gods. Divided into ten grids, each grid is divided into four small grids; Its ten squares are printed with numbers representing good luck and bad luck. They are "Ding": Fuxing and Caiwang. "Hazard": Foot-and-mouth disease became extinct as soon as it died. "Wang": Tiande's happy event is a blessing. Bitterness: The ghost who lost his official robbed money and had no children. "Righteousness": Daji is prosperous and beneficial to Tianku. "Official": Prosperous, prosperous. "Death": Don't retire to your hometown and lose money. "Xing": Deng Kegui Ziwang. "Lost": widowed, performing official duties, paying back the money. Caijing: Welcome Fu Liuhe to Bao Caide.