7 - Measuring atmospheric pressure

Summary

Atmospheric pressure is one of the most important of all meteorological elements. Fortunately, it is also the easiest of all to measure, particularly with modern sensors, and even basic instruments such as household aneroid barometers or smartphones can provide reasonably accurate readings. To ensure consistent and reliable readings for professional applications, for instance aviation requirements, it is essential that pressure sensors are correctly exposed: World Meteorological Organization recommendations on exposure and instrument accuracy are included. Instructions are given to correct or ‘reduce’ observed atmospheric pressure readings to a standard level, usually mean sea level (MSL), and to check and adjust the calibration of pressure sensors to avoid calibration drift, which can become substantial if not corrected. Methods for doing this are explained, with examples.