SUUNTO Elementum Terra - Manual (Page 26)

The measuring interval is 1, 5 or 10 seconds (depending on vertical speed).
The sea level air pressure value stays steady and the altitude reading changes
according to your vertical movement.
NOTE: The barometric trend arrow flattens out when altitude is measured for
over a 6-hour period, as the device does not change the sea level air pressure value
while measuring altitude.
USER EXAMPLE: CORRECTING ALTITUDE VALUE
You are hiking uphill and the weather is getting clear. The sea level air pressure on
the outer rim is the same as before starting the hike upwards. You set the correct
altitude on the watch based on the map. The correct sea level air pressure is
calculated and shown on the outer rim of the display. The value is now higher than
before, which indicates clear weather. The barometric trend arrow remains the
same as before starting the hike.
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