User manual

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ABOUT ALTITUDE AND AIR PRESSURE
MEASUREMENTS
Altimeter
Generally, air pressure and temperature decrease as altitude increases. This
watch bases its altitude measurements on International Standard Atmos-
phere (ISA) values stipulated by the International Civil Aviation Organization
(ICAO), which define relationships between altitude, air pressure, and tem-
perature.
540 hPa/mb
616 hPa/mb
701 hPa/mb
795 hPa/mb
899 hPa/mb
1013 hPa/mb
472 hPa/mb
0 m
500 m
1000 m
1500 m
2000 m
2500 m
3000 m
3500 m
4000 m
4500 m
5000 m
5500 m
6000 m
8.5°C
2°C
–4.5°C
–11°C
–17.5°C
–24°C
15°C
About 6.5°C
per 1000 m
About 6.7 hPa/mb per 100 m
About 7 hPa/mb per 100 m
About 8 hPa/mb per 100 m
About 9 hPa/mb per 100 m
About 10 hPa/mb per 100 m
About 11 hPa/mb per 100 m
About 12 hPa/mb per 100 m
ALTITUDE AIR PRESSURE TEMPERATURE
Source: International Civil Aviation Organization
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.
Barometer
Barometric pressure indicates changes in the atmosphere, and by monitoring
these changes you can predict the weather with reasonable accuracy. Rising
barometric 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.
Height of building 130 m
(Relative altitude)
Rooftop at an altitude of
230 m above sea level
(Altitude above sea level)
Sea