Changes in atmospheric pressure can affect everything from the weather to your quality of sleep. In this lesson, we’ll discuss the definition and uses of a tool used to measure atmospheric pressure: the aneroid barometer.
You toss and turn at night, unable to sleep.
You have no idea why this might be. You didn’t drink too much coffee or soda. You didn’t go for a run too close to bedtime. You didn’t eat too many sweets today.When you go to school or work, you tell a few friends or coworkers about it, and you discover that many others had the same unfortunate experience last night. Oddly enough, this lack of sleep may be connected to something you may not have thought of – the weather.
Humans can actually perceive changes in atmospheric pressure, which can be thought of as the weight of the air in a particular area. Now, we don’t have a sixth sense for it. It’s not like someone can close their eyes and say, ‘The pressure just changed by two percent!’ But, our tissues and muscles can tell when pressure is changing significantly.You may have heard someone at one time or another say something along the lines of, ‘Whenever my knee hurts, it’s going to rain.’ This might actually be true, but it’s more likely a perception of the pressure changing and not necessarily impending rain. At night, if pressure changes drastically, a wide range of people may experience a sleepless night.Several factors affect the measurement of atmospheric pressure, including the temperature and amount of moisture in the air.
Changes in pressure cause changes in weather – sometimes good, sometimes very bad. Any tool designed to measure atmospheric pressure is called a barometer, and one type – and the focus of this lesson – is the aneroid barometer.
How It Works
Most modern barometers are digital and incredibly accurate. Early barometers used various liquids (usually mercury) to measure changes in pressure. As pressure increased, it would push down on the liquid and increase the measurement. Using glass and liquid leads to a rather fragile tool, though, so a French scientist invented the aneroid barometer in the mid 1800s.Instead of using liquid, it uses a metal box made of a mixture of beryllium and copper to measure the atmospheric pressure.
This box is called an aneroid cell. The aneroid cell expands and shrinks as the atmospheric pressure goes down and up.
Due to its sturdy construction, the aneroid barometer has many uses.
It is common to find aneroid barometers in homes, on boats, and in small planes. If you have ever seen a barometer hanging on a wall of a house and it just contains a dial with numbers (it looks a lot like a clock), that is an aneroid barometer.The other primary use of an aneroid barometer is in meteorology. Meteorologists tend to prefer aneroid barometers because it is very easy to measure even slight changes in atmospheric pressure.
It is important to measure atmospheric pressure (the weight of the air in an area) because the weather is often dependent on the pressure.
Unlike early barometers, which used glass and liquids like mercury to measure pressure, aneroid barometers use a special metal box called an aneroid cell to measure atmospheric pressure. This construction allows the barometer to be sturdier and easier to read. For these reason, meteorologists often prefer aneroid barometers.