What is the difference between Absolute barometric pressure and Sea Level barometric pressure?
Absolute barometric pressure is the true pressure at any known location at any time. This number is unstable and not constant. Sea Level barometric pressure is its equivalent pressure corresponded to sea level. It is the station pressure reduced to sea level by an appropriate altitude dependant formula. The information found at www.weather.gov or your local airport has already been adjusted to sea level and this is the information to use while calibrating your Highgear barometer.
