Altimeter Precautions; Displayed Altitude Values (Relative Altitude) - Casio WSD-F21HR User Manual

Altimeter Precautions

Do not use this watch while skydiving, hang gliding, paragliding, gyrocopter
●
flying, glider flying, or engaged in other activities where altitude changes
suddenly.
Altitude readings produced by this watch are not intended for special-
●
purpose or industrial level use.
In an aircraft, the watch measures the in-cabin pressurized air pressure, so
●
readings will not match altitudes announced by the crew.
Large changes in barometric pressure due to atmospheric conditions, large
●
temperature changes, or subjecting the watch to strong impact may make
correct readings impossible.

Displayed Altitude Values (Relative Altitude)

The two ways to express altitude are described below.
Relative Altitude:
This is the difference in the altitudes between two locations.
Example: Height measured from the ground to the top of a building (A)
Sea Level Altitude (Elevation):
Altitude measured from sea level.
Example: Height measured from sea level to the top of a building (B)
Your watch's Altimeter use a pressure sensor to measure barometric
pressure, and then calculates and displays relative altitude based on the
measured value. The altitude values displayed by your watch are based on
International Standard Atmosphere (ISA) relative altitude data defined by the
International Civil Aviation Organization (ICAO).
Sea level
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