La Crosse Technology WS-9020U Instruction Manual page 14

2. Press and release the SET key to confirm selection and to enter
the Relative Pressure Value setting.
Note:
The default reference pressure value of the barometer is 29.91 inHg
(1013 hPa). For an exact measurement it is necessary to first adjust
the barometer to your local relative air pressure (related to
elevation above sea level). Ask for the present atmospheric pressure
of your home area (Local weather service, calibrated instruments in
public buildings, airport).
RELATIVE PRESSURE VALUE SETTING
The default relative pressure value is 29.91 inHg (1013 hPa). This
corresponds to the average air pressure. Pressure below this is referred
to as low-pressure area (weather to become worse), pressure above as
high-pressure area (weather to improve). The relative air pressure can
be manually set to another value within the range of 28.35 to 30.72 inHg
(960 – 1040 hPa) for a better reference.
1. The current relative pressure value will start flashing
2. Use the MAX/+ or MIN/- key to increase or decrease the value.
Keep holding the key allows the value to advance faster.
3. Press and release the SET key to confirm selection and to enter
the Language display setting.
Note:
This calibration facility is useful for those users living at various
elevations above sea level, but wanting their air pressure display based
on sea level elevation.
LANGUAGE DISPLAY SETTING:
14
Digit flashing