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 | Temperature |
4000 m |
|
|
| 616 hPa |
| 3500 m | |||
3000 m |
|
|
| 701 hPa |
| 2500 m | |||
2000 m |
|
|
| 795 hPa |
| 1500 m | |||
1000 m |
|
|
| 899 hPa |
| 500 m | |||
0 m |
|
|
| 1013 hPa |
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 6.5°C | ||
|
| |
2°C |
| per 1000 m |
8.5°C |
| |
15°C |
| |
Source: International Civil Aviation Organization