1. Keep the compass level, close to or parallel to the edge of the measured object.

2. Slide the turntable so that the hairpin head of the magnetic needle coincides with two points on the red line of the compass base.

3. Just locate the reading direction of the layer pressed by the transparent line.

Extended data:

Precautions for use

1. When using the compass, hold the outer disk of the compass with both hands, separate your feet slightly, and then put the compass on your chest. Keep the compass level. You can't keep high and low first, and then start measuring squares with your back as the seat and your face as the direction.

2. The crosshair silk on the compass should coincide with the front, back, left and right positions of the house. If the crosshair is not vertical, then the measured sitting posture will be biased.

3. After fixing the fishing line, move the inner plate with both thumbs. When the inner plate rotates, Tianchi will also rotate with it until the inner plate stops and coincides with the red line of Tianchi.

4. The end of the magnetic needle with a small hole must coincide with two small points on the red line, and the position cannot be reversed. At this time, it shows that the fishing line sitting in the opposite direction intersects with each layer of the inner disk. All kinds of data and information we are looking for are displayed in the area where this fishing line passes through and covers.

Baidu encyclopedia-compass