Compass orientation measurement: how to use a compass or guide (north) needle to measure the orientation of a house.
Before using a compass or compass, the following points need special attention:
1, you must first remove all ironware, electrical appliances (mobile phones, walkman ……) or items that will interfere with the magnetic field of the compass.
2. Note that there are no ironware, mobile phones, telephone poles, electric boxes, electric towers, etc. This will interfere with the electromagnetic field near the measurement location.
3. The disk surface of compass or compass (north) needle must be horizontal, and the pointer cannot rise or fall at the same time. At the same time, we should also pay attention to whether the joint between the compass surface and the disk body is tight, and there should be no looseness or damage.
4, check whether the compass or guide (north) needle is normal, if bent, it shall not be used.
Compass usage:
When measuring the direction of a fixed object:
Step 1: put the compass flat so that it is close to or parallel to the edge of the measured object.
Step 2: Slide the turntable to make the hairpin head of the magnetic needle match the two points on the red line of the compass base.
Step 3: Locate the reading direction of the layer pressed by the transparent line.
Measure the direction of furnace: level the compass. Near the edge of the stove. If the furnace is made of iron, it will affect the swing of the magnetic needle, so it should retreat two or three feet vertically. The edge of the compass is parallel to the edge of the stove. Slide the turntable so that the hairpin head of the magnetic needle matches the two points on the red line. Reading direction.
First of all, the correct compass:
Figure a?
Hold the outer disk with both hands left and right, and separate your feet slightly.
Put the compass between the chest and abdomen, and keep it horizontal, not high on the left and low on the right, nor high on the front and low on the back.
Adjust the compass. The crosshair above the compass should be parallel to the door of the house (see Figure A).
Adjust the pointer direction:
Figure b Tianchi?
Figure C Adjust Tianchi?
After fixing the position of the crosshairs, you need to start adjusting the direction of the pointer in Tianchi.
Move the inner disk with both thumbs. When the inner disk rotates, Tianchi will rotate with it. Turn the inner disk until the magnetic needle stops (Figure C) and coincides with the red line of Tianchi Lake.
Direction discrimination method
Figure h top view