Unless some way of standardizing air pressure with elevation
was used, we would have the greatest difficulty in using
smaller variations in overall air pressure to help us
predict the weather. Mount your barometer where it is easy to see and adjust. Call the weather service, the airport or a news outlet to obtain a current barometric reading. When you join, you'll also receive, And I promise that you won't get spammed, and that your sign up details will remain totally confidential. OK, we know that air pressure decreases by 1 millibar forevery 8.2 meters we gain in height, so setting a barometershould be a simple matter if we know the elevation. Where the troposphere is thicker, the pressure is higher, and
it is lower where the troposphere is thinner, and these
highs and lows move across the planet. Aneroid barometer movements are generally set at production in order to give the correct reading at sea level (the standard measurement point). Check it every year or so. It can be used both for assisting in forecasting weather and for determining altitude. It is this easy to set your barometer, you can now rely upon the results. So there's no need to be worried if you can't manage a perfect match with another weather station. If not, continue to compare and adjust untilthey do.Avoid exceptionally hot or cold days, times when the weatheris changing or stormy, and windy days, all of which canlead to noticeable local pressure variations.Most home weather stations will allow you to set a referencesea level pressure equivalent, and all later readingswill be based on that. Set your barometer The chamber reacts to the rise and fall of outside atmospheric pressure by contracting or expanding, and a needle is used to display a reading.Calibrate your barometer only during a period of fair weather, not during stormy weather. So if we assume the top of the troposphere is at the same
height over a large area, then higher points on the land's
surface will have less air above them. OK, we know that air pressure decreases by 1 millibar forevery 8.2 meters we gain in height, so setting a barometershould be a simple matter if we know the elevation.Well, yes and no. Copyright 2020 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. Air pressure measures the pressure
caused by the weight of a column of air, extending to the top
of the atmosphere. Compare the two values over the next few days, preferablyin calm clear conditions during the middle part of the day.If the two values continue to correspond your problems are solved.
(This is the lighter coloured needle).