Correction of Barometer Reading for Gravity

The height of the column of a mercury barometer is affected by the force of gravity, which changes with latitude and is approximately equal along any parallel of latitude. The average gravitational force at latitude 45°32’40” is used as the standard for calibration.

This calculation provides a correction to convert the observed reading at any other latitude to the corresponding value at latitude 45°32’40”.

This correction does not apply to aneroid barometers.