SLAU292G November 2009 – July 2015
Press * until the altimeter alarm mode is active (see Figure 3-1 for details). The altitude can be shown in metric or imperial units. In 12H time mode, the altitude is shown in imperial units. In 24H time mode, the altitude is shown in metric units. The altitude is measured only when the altimeter mode is active, and measurement are made in intervals of 1 second.
The implementation of the altitude algorithm is done according to the VTI's application report AN33 without any additional low-power optimizations. Therefore, the altimeter is active only in altimeter mode. In addition, a timeout deactivates the measurements after 60 minutes. Altitudes above sea level are indicated with a small arrow pointing up in the upper LCD line, left of the altitude. Altitudes below sea level are indicated with a small arrow pointing down.
The altimeter algorithm is based on the air pressure and the ambient temperature. Therefore, changes in air pressure affect the altitude accuracy. For precise measurements, the altimeter must be calibrated manually for weather changes.
NOTE
For most accurate altitude measurement, the wrist module must be fully exposed to the ambient temperature (that is, the wrist module should not be worn directly on the arm), because temperature is part of the altitude measurement (see Section 3.2.1.3).
Secondary function: Re-activate altimeter after timeout
Set function: Altitude calibration