First of all, the magnetic needle of a compass should be straight. If the magnetic needle is not straight, it is easy to have direction deviation.
Second, the red line at the bottom of Tianchi refers to the north and south. Aim the magnetic needle at the red and black line, and its south side should be opposite to the "noon" center of the earth branch, and its north side should be opposite to the "secondary" center of the earth branch.
Third, the heavenly heart should be at right angles. Modern compasses are equipped with a red cross, and the two lines must be perpendicular to each other.
Fourth, the magnetic needle should rotate flexibly. Only a flexible magnetic needle can truly reflect the magnetic field.
5. The inner disk must be written neatly and clearly. sandal wood
Six, the outer disk must form a flat square. There must be no distortion on the disk surface.
Seven, pay attention to the material. Wooden compasses are easy to deform if the water is not dry before making, and compasses made of metal or organic materials are easy to be extruded and deformed.
Eight, the color is right. Feng shui compasses often use colors to represent yin and yang, so pay special attention to whether the colors on the compass are correct.