2. Press either the [ON OFF] or the [QUICK] button to toggle between "YES" and "nO".
3. Press the [MODE] button to accept the preference "YES" and exit.
The logbook history is erased and a new starting date will be set to begin new cumulative
measurements.
NOTE: Setup mode will automatically exit if left idle for more than one minute.
We recommend that the logbook history be cleared prior to beginning logbook
recording(s).
3.6 EFFECT OF AIR TEMPERATURE ON ALTITUDE MEASUREMENT
The atmospheric pressure means the weight of air mass above the observer: at a higher
altitude there is less air than at a lower altitude. The principle of an altimeter is to
measure the different air pressure between different altitudes.
The outside temperature affects the air weight. Consequently the air pressure difference
between two altitudes is also dependant on temperature.
The altitude calculation of the Observer is based on the air pressure at certain normal
temperatures. Each altitude has a definitive normal temperature. The normal
temperatures at each altitude are presented in Table 1.
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