# Questions And Answers; Power Supply - Casio 3148 Operation Manual

Casio watch operation guide

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
conditions.
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
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.
Altitude
Air Pressure
616 hPa
About 8 hPa per 100 m
4000 m
3500 m
701 hPa
3000 m
About 9 hPa per 100 m
2500 m
795 hPa
2000 m
About 10 hPa per 100 m
1500 m
About 11 hPa per 100 m
899 hPa
1000 m
500 m
About 12 hPa per 100 m
0 m
1013 hPa
14000 ft
19.03 inHg
12000 ft
About 0.15 inHg per 200 ft
10000 ft
22.23 inHg
8000 ft
About 0.17 inHg per 200 ft
6000 ft
About 0.192 inHg per 200 ft
25.84 inHg
4000 ft
2000 ft
About 0.21 inHg per 200 ft
0 ft
29.92 inHg
Source: International Civil Aviation Organization
• Note that the following conditions will prevent you from obtaining accurate
When air pressure changes because of changes in the weather
Extreme temperature changes
When the watch itself is subjected to strong impact
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
different places.
Height of building 130 m
(relative altitude)
Precautions Concerning Simultaneous Measurement of Altitude and
Temperature
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
measurements.
• 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.
Operation Guide 3148
Temperature
–11°C
–4.5°C
per 1000 m
2°C
8.5°C
15°C
16.2°F
30.5°F
per 1000 ft
44.7°F
59.0°F
Rooftop at an altitude of
230 m above sea level
(absolute altitude)
Sea Level

### Power Supply

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
pointing at a light source.
• 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
clothing, etc.
• 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.
Important!
• Storing the watch for long periods in an area where there is no light or
wearing it in such a way that it is blocked from exposure to light can cause
rechargeable battery power to run down. Be sure that the watch is exposed
to bright light whenever possible.
• This watch uses a special rechargeable battery to store power produced by
the solar cell, so regular battery replacement is not required. However, after
very long use, the rechargeable battery may lose its ability to achieve a full
charge. If you experience problems getting the special rechargeable battery
to charge fully, contact your dealer or CASIO distributor about having it
replaced.
• Never try to remove or replace the watch's special battery yourself. Use of
the wrong type of battery can damage the watch.
• All data stored in memory is deleted, and the current time and all other
to Level 5 and when you have the battery replaced.
• Turn on the watch's Power Saving function and keep it in an area normally
exposed to bright light when storing it for long periods. This helps to keep
the rechargeable battery from going dead.
Battery Power Indicator and Recover Indicator
The battery power indicator on the display shows you the current status of the
rechargeable battery's power.
Level
Battery Power Indicator
1
2
3
l
Battery power
indicator
4
c
5
• The flashing
LOW
indicator at Level 3 tells you that battery power is very
low, and that exposure to bright light for charging is required as soon as
possible.
• At Level 5, all functions are disabled and settings return to their initial
factory defaults. Once the battery reaches Level 2 (indicated by M indicator)
after falling to Level 5, reconfigure the current time, date, and other
settings.
• Display indicators reappear as soon as the battery is charged from Level 5
to Level 2.
• Leaving the watch exposed to direct sunlight or some other very strong light
source can cause the battery power indicator to show a reading temporarily
that is higher than the actual battery level. The correct battery level should
be indicated after a few minutes.
• Performing multiple sensor, illumination, or
beeper operations during a short period may
cause LMH (recover) to appear on the display.
Illumination, alarm, countdown timer alarm,
hourly time signal, and sensor operations will
be disabled until battery power recovers.
After some time, battery power will recover and
LMH (recover) will disappear, indicating that
the above functions are enabled again.
Recover indicator
• Even if battery power is at Level 1 or Level 2, the Barometer/Thermometer
Mode or Altimeter Mode sensor may be disabled if there is not enough
voltage available to power it sufficiently. This is indicated by LMH (recover)
on the display.
• If LMH (recover) appears frequently, it probably means that remaining
battery power is low. Leave the watch in bright light to allow it to charge.
Solar cell
Function Status
All functions enabled.
All functions enabled.
Illumination, beeper, and
sensor operation disabled.
Except for timekeeping and
the C (charge) indicator, all
functions and display
indicators disabled.
All functions disabled.
7