32
4. Press
the
ALARM
key once to return to the normal display mode.
In case the wind speed exceeds the condition for high wind speed alarm, the value
will be flashing, along with the corresponding high alarm icon ("HI AL"). And the
buzzer will ring for 2 minutes. User may press any key to stop the sound.
HYSTERESIS
To compensate for fluctuation of the measured data, which may cause the weather
alarm to sound constantly if the measured reading is close to your set level, a
hysteresis function has been implemented for each weather alarm. For example, if the
high temperature alarm is set to +77°F and the current value moves to +77°F, the
alarm will be activated (if it has been enabled). Now when the temperature drops to
+76.8°F or below and thereafter again increases to 77°F, the data will be
blinking, but no alarm will be activated. It has to drop to below +75.2°F (with a pre-set
hysteresis of 1.8°F) so that the alarm can be produced again. Hysteresis values for
the various weather data types are given in the following table:
Weather data
Hysteresis
Temperature
1.8°F
Humidity
3% RH
Wind speed
3.1 mph
Note:
The temperature or humidity data will keep on flashing even after a key has been
pressed to stop the alarm or buzzer has been switched off, to indicate that the current
weather condition is out of the pre-set limit(s)
33
WEATHER FORECAST AND WEATHER TENDENCY
WEATHER FORECASTING ICONS:
Weather forecasting icons is displayed in any of the following combinations at the right
bottom part of LCD:
For every sudden or significant change in the air pressure, the weather icons will
update accordingly to represent the change in weather.
(Every time a new average pressure value has been obtained (once per minute), this
value is compared with an internal reference value. If the difference between these
values is bigger than the selected weather tendency sensitivity, the weather-icon
changes, either for worse or for better. In this case, the current pressure value
becomes the new weather tendency reference.)
If the icons do not change, either the air pressure has not changed or the change has
been too small for the Weather Center to register. So you may adjust the "sensitivity"
of the pressure change checking in the setting mode
–
see
WEATHER TENDENCY
SENSITIVITY VALUE SETTING
above.
Sunny
TENDENCY
change in the air press r
Cloudy with sunny
intervals
TENDENCY
Rainy
TENDENCY
