Operation Guide 3070 ( B )
About the Auto Light Switch
Turning on the auto light switch causes illumination to turn on, whenever you
position your wrist as described below in any mode.
Note that this watch features a "Full Auto EL Light", so the auto light switch
operates only when available light is below a certain level. It does not
illuminate the display under bright light.
• The auto light switch is always disabled, regardless of its on/off setting,
when any one of the following conditions exists.
While an alarm is sounding
During sensor measurement
While a bearing sensor calibration operation is being performed in the
Digital Compass Mode
While a receive operation is in progress in the Receive Mode
Moving the watch to a position that is parallel to the ground and then tilting
it towards you more than 40 degrees causes illumination to turn on.
• Wear the watch on the outside of your wrist.
• Always make sure you are in a safe place whenever you are reading
the display of the watch using the auto light switch. Be especially
careful when running or engaged in any other activity that can result
in accident or injury. Also take care that sudden illumination by the
auto light switch does not startle or distract others around you.
• When you are wearing the watch, make sure that its auto light switch
is turned off before riding on a bicycle or operating a motorcycle or
any other motor vehicle. Sudden and unintended operation of the auto
light switch can create a distraction, which can result in a traffic
accident and serious personal injury.
To turn the auto light switch on and off
In the Timekeeping Mode, hold down L for about three seconds to toggle the
auto light switch on (A.EL displayed) and off (A.EL not displayed).
• The auto light switch on indicator (A.EL) is on the display in all modes while
the auto light switch is turned on.
• The auto light switch turns off automatically whenever battery power drops
to Level 4.
• Illumination may not turn on right away if you raise the watch to your face
while a barometric pressure or altitude measurement operation is in
Questions & Answers
Question: What causes incorrect direction readings?
• Incorrect bidirectional calibration. Perform bidirectional calibration.
• Nearby source of strong magnetism, such as a household appliance, a
large steel bridge, a steel beam, overhead wires, etc., or an attempt to
perform direction measurement on a train, boat, etc. Move away from large
metal objects and try again. Note that digital compass operation cannot be
performed inside a train, boat, etc.
Question: What causes different direction readings to produce different
results at the same location ?
Answer: Magnetism generated by nearby high-tension wires is interfering with
detection of terrestrial magnetism. Move away from the high-tension
wires and try again.
Question: Why am I having problems taking direction readings indoors ?
Answer: A TV, personal computer, speakers, or some other object is
interfering with terrestrial magnetism readings. Move away from the
object causing the interference or take the direction reading
outdoors. Indoor direction readings are particularly difficult inside
ferro-concrete structures. Remember that you will not be able to take
direction readings inside of trains, airplanes, etc.
Question: How does the barometer work?
Answer: Barometric pressure indicates changes in the atmosphere, and by
monitoring these changes you can predict the weather with
reasonable accuracy. Rising atmospheric pressure indicates good
weather, while falling pressure indicates deteriorating weather
The barometric pressures that you see in the newspaper and on the
TV weather report are measurements corrected to values measured
at 0 m sea level.
Question: How does the altimeter work?
Answer: Generally, air pressure and temperature decrease as altitude
• Note that the following conditions will prevent you from obtaining accurate
There are two standard methods of expressing altitude: Absolute altitude and
relative altitude. Absolute altitude expresses an absolute height above sea
level. Relative altitude expresses the difference between the height of two
Precautions Concerning Simultaneous Measurement of Altitude and
Though you can perform altitude and temperature measurements at the same
time, you should remember that each of these measurements requires
different conditions for best results. With temperature measurement, it is best
to remove the watch from your wrist in order to eliminate the effects of body
heat. In the case of altitude measurement, on the other hand, it is better to
leave the watch on your wrist, because doing so keeps the watch at a
constant temperature, which contributes to more accurate altitude
• To give altitude measurement priority, leave the watch on your wrist or in
any other location where the temperature of the watch is kept constant.
• To give temperature measurement priority, remove the watch from your
wrist and allow it to hang freely from your bag or in another location where
it is not exposed to direct sunlight. Note that removing the watch from your
wrist can affect pressure sensor readings momentarily.
This watch is equipped with a solar cell and a special rechargeable battery
(secondary battery) that is charged by the electrical power produced by the
solar cell. The illustration shown below shows how you should position the
watch for charging.
Example: Orient the watch so its face is
• The illustration shows how to position a
watch with a resin band.
• Note that charging efficiency drops when
any part of the solar cell is blocked by
• You should try to keep the watch outside
of your sleeve as much as possible.
Charging is reduced significantly if the
face is covered only partially.
increases. This watch bases its altitude measurements on
International Standard Atmosphere (ISA) values stipulated by the
International Civil Aviation Organization (ICAO). These values define
relationships between altitude, air pressure, and temperature.
About 8 hPa per 100 m
About 9 hPa per 100 m
About 10 hPa per 100 m
About 11 hPa per 100 m
About 12 hPa per 100 m
About 0.15 inHg per 200 ft
About 0.17 inHg per 200 ft
About 0.192 inHg per 200 ft
About 0.21 inHg per 200 ft
Source: International Civil Aviation Organization
When air pressure changes because of changes in the weather
Extreme temperature changes
When the watch itself is subjected to strong impact
Height of building 130 m
pointing at a light source.
per 1000 m
per 1000 ft
Rooftop at an altitude of
230 m above sea level