Module No. 3452

Altitude Reading Precautions

Effects of Temperature

When taking altitude readings, take the steps below to keep the watch at as stable a temperature as possible. Changes in temperature can affect altitude readings.

  • Take readings with the watch on your wrist.
  • Take readings in an area where temperature is stable.

Altitude Readings

  • 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.

Altitude Readings (Relative Altitude)

This watch uses International Standard Atmosphere (ISA) relative altitude data defined by the International Civil Aviation Organization (ICAO). Barometric pressure generally becomes lower as altitude increases.

Correct measurement may not be possible under the conditions below.

  • During unstable atmospheric conditions
  • During sudden temperature changes
  • After the watch has been subjected to strong impact

Measured Altitude Value Adjustment Using GPS Signal Data

When using navigation while receiving GPS signals, measured altimeter values are automatically adjusted in accordance with GPS signal data. Note, however, that this may result in some difference between the measured value and the actual altitude. Also note that the measured altitude value adjustment operation using GPS signal data may take a few minutes. The adjustment operation may take even longer, depending on your current environment. Regular manual adjustment of the measured altitude value using locally available information is recommended. The watch will not use GPS signal data to adjust measured altitude values for one hour after you adjustment the measured altitude value manually.