Barometers are meteorological devices that incorporate vacuum pressure to measure the pressure of outside air. These devices have a long history of use dating back to the early 17th century, and for hundreds of years prior to that scientists throughout Europe were investigating ways that the barometer could be used to determine a number of different things about the air and the world. Basically, a barometer tells the pressure of air either outside or inside of a device, and there are far more uses for a barometer than just the simple weather prediction device that they were originally designed for. Other types of barometers are available that perform all sorts of different tasks.
Barometers have long been used for measuring weather patterns. Air pressure from high and low pressure fronts that move throughout the globe is useful in determining or predicting what the weather will be like at a given time and on a given date. This is the most basic and historical use for barometers, and these devices help determine whether it will be hot or cold, or what the likelihood of precipitation might be on any given date.
Pressure Reading Devices
Other types of barometers include the pressure devices found on pressure cookers, canning utensils and steam boilers. Any time an air pressure inside of a vessel has to be measured, a barometer is the most useful tool to perform this measurement. While they do not look like weather barometers, these pressure reading instruments are performing essentially the same task as their meteorological cousins.
Other types of barometers include air pressure reading devices that report the air speed of an aircraft. Often called pitot tubes, these devices are a type of barometer that senses the pressure of air moving against an aircraft and then converts this reading into an estimated air speed indicator, allowing pilots to determine how fast they are moving relative to the air around them.
Yet another type of use for barometers on airplanes or elsewhere is as a measure of altitude. Since air gets thinner and lighter the higher up you travel into the atmosphere, a barometer can be useful for determining how high above sea level you are. Barometers that have this function are often called altimeters or altitude meters.