Timex Intelligent Quartz Manual page 192

work properly in that same location. If the compass
is calibrated away from such objects, it will not work
properly near them. For best results, calibrate in the area
of intended use.
In calibrating and taking headings, it is important, as with
all compasses, to keep the compass level. Calibrating or
taking a heading when the watch is not level can result
in large errors. Also avoid areas that may exhibit higher
than normal concentrations of hard and soft iron, as they
may cause inaccurate headings. Whenever a heading is
suspect, recalibrate.
Do not store the watch near any source of magnetism,
such as a computer, appliance, or television, as the
watch can take on a magnetic charge, yielding inaccurate
headings. Typical accuracy of wrist-worn instruments is
within +/- 10 degrees.
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