Operation Guide 2891

Digital Compass Reference

❚What is a digital compass?

The Earth is like a giant magnet with a north pole and a south pole. The magnetism of the Earth is called “terrestrial magnetism”. The magnetic sensor of your watch is a magnetic compass that detects terrestrial magnetism to determine direction.

Earth

❚Magnetic compass north reading

The northerly direction detected by a magnetic compass is “magnetic north,” which is different from “true north”. Depending on your location on the globe, the magnetic north indicated on a compass is actually east or west of true north. The angle that is formed by the difference between magnetic north and true north is called the “declination”.

The magnetic north pole is located north of Canada, while the magnetic south pole is located south of Australia. In Japan, the declination angle is 5 degrees (around Kagoshima) to about 9 degrees (around Hokkaido) west.

Magnetic north pole

Magnetic south pole

❚Using the Compass in an Automobile

The entire body of a vehicle may be magnetized, which will make proper direction readings impossible. By performing 2-point calibration, however, you can use the compass to take approximate readings while riding in an automobile.

•See “To perform 2-point calibration” for information about how to perform 2-point calibration.

Important!

Never try to perform 2-point calibration while driving. Doing so is very dangerous and creates the risk of serious accident.

1. First, park the vehicle in a

2. At a location inside the

safe area where you can

vehicle that is away from

turn it around 180 degrees.

its equipment and body,

 

use the 2-point calibration

 

screen to calibrate the first

 

point.

3. Turn the vehicle around 180 degrees, and then calibrate the second point.

Precautions During Calibration

•When performing 2-point calibration, perform calibration of the first point and the second point in the same location.

•Keep as far away from possible from the vehicle’s equipment, body, and other possible sources of magnetism.

•Depending on the condition of the magnetism of the vehicle, proper direction readings may not be possible.

•Magnetism differs from vehicle to vehicle. Be sure to perform 2-point calibration whenever you change from one vehicle to another.

•You should also perform 2-point calibration again if you change position (from the driver’s seat to the back seat, etc.) within the same vehicle.

Digital Compass Troubleshooting

Proper direction readings will not be possible in areas exposed to unstable magnetism or areas where something is interfering with terrestrial magnetism.

Also note that accurate direction readings are not possible if you do not perform the required operations correctly. Check the following points if you suspect that direction readings are wrong for some reason.

❚The displayed direction is wrong.

Cause 1: You did not perform 2-point calibration.

Remedy: Correctly perform 2-point calibration.

Cause 2: There is source of strong magnetism nearby.

Remedy: If any of the following objects are nearby, move away and try taking a direction reading again.

❚The watch shows different direction

readings at the same location.

Cause: Unstable magnetism caused by high-voltage lines nearby.

Remedy: Change to a different location and try again.

Electrical equipment, large bridge, structure made with steel columns, electrical train wires, automotive vehicle, boat, etc.

Cause 3: You are in an area where magnetism is fluctuating.

Remedy: Move away from the objects described above.

❚Correct direction readings are not

possible indoors.

Cause: A nearby TV, computer, or other device is disturbing the directionality of the magnetism.

Remedy: Change to another location or move outside and try again. Note that correct direction readings are not possible inside of a ferro-concrete structure.

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