54
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
+25°C and the current value moves to +25°C, the
alarm will be activated (if it has been enabled).
Now when the temperature drops to +24.88°C or below and thereafter again increases
to 25°C, the data will be blinking, but no alarm will be activated. It has to drop
to below +24°C (with a pre-set hysteresis of 1°C) so that the alarm can be produced
again. Hysteresis values for the various weather data types are given in the table.
Note:
The temperature or humidity data will keep flashing even after a key has been
pressed to stop the alarm has been switched off to indicate that the current weather
condition is out of the pre-set limit(s)
WEATHER FORECAST AND WEATHER TENDENCY
WEATHER FORECASTING ICONS:
Weather forecasting icons are displayed in any of the following combinations:
Sunny
Cloudy with sunny intervals
Rainy
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.
However, if the icon displayed is a sun or raining cloud, there will be no change of icon if
the weather gets any better (with sunny icon) or worse (with rainy icon) since the icons
are already at their extremes.
The icons displayed forecasts the weather in terms of getting better or worse and not
necessarily sunny or rainy as each icon indicates. For example, if the current weather is
cloudy and the rainy icon is displayed, it does not mean that the product is faulty
Weather data Hysteresis
Temperature
1°C
Humidity
3% RH
Pressure
1 hPa
Wind speed
10 km/h
