Vaisala HM40 - Manual (Page 28)

27
Pressure
In the Pressure setup screen, you
can set the current ambient
pressure. The pressure information is
used when calculating certain
humidity parameters, such as mixing
ratio (symbol x).
If the ambient pressure differs
significantly from the default setting
of 1.0132 bar (due to high altitude,
for example), set the correct
pressure value so that the HM40
meter can calculate the
measurement correctly.
Backlight
Always on: Screen is always lit. This
option will shorten the battery life
significantly.
Always off: Screen is always unlit.
This option provides the best
battery life.
Delay (30s): Backlight will
automatically turn on when the user
presses any button. The backlight
will turn off after 30 seconds of
inactivity.
Dimmed: Screen is always lit with a
dim backlight.