It's called "barometric" pressure because an instrument called a barometer is used to measure air pressure.
(It; 's called; barometric" pressure; because an instrument called a barometer is used to measure air pressure) (an instrument; called; a barometer) (an instrument called a barometer; is used; to measure air pressure) (an instrument called a barometer; to measure; air pressure)
It an instrument an instrument called a barometer an instrument called a barometer
's called called is used to measure
barometric" pressure because an instrument called a barometer is used to measure air pressure
a barometer
to measure air pressure
air pressure