Casio 3069 Manual page 105

Question: Why am I having problems taking direction readings indoors ?
Answer: A TV, personal computer, speakers, or some other object is
interfering with terrestrial magnetism readings. Move away from the
object causing the interference or take the direction reading
outdoors. Indoor direction readings are particularly difficult inside
ferro-concrete structures. Remember that you will not be able to take
direction readings inside of trains, airplanes, etc.
Question: How does the barometer work?
Answer: Barometric pressure indicates changes in the atmosphere, and by
monitoring these changes you can predict the weather with
reasonable accuracy. Rising atmospheric pressure indicates good
weather, while falling pressure indicates deteriorating weather
conditions.
The barometric pressures that you see in the newspaper and on the
TV weather report are measurements corrected to values measured
at 0 m sea level.
E-103