What is a barometer used to measure?

A barometer is a scientific instrument used to measure atmospheric pressure, also called barometric pressure. The atmosphere is the layers of air wrapped around the Earth.

How does a barometer tube work?

The barometer works by balancing the weight of mercury in the glass tube against the atmospheric pressure, much like a set of scales. If the weight of mercury is less than the atmospheric pressure, the mercury level in the glass tube rises (high pressure).

What type of barometer uses liquid and a tube?

Mercury barometers
The principle of the mercury barometer was discovered by the Italian physicist Evangelista Torricelli in about 1643. That principle can be illustrated in the following manner. A long glass tube is sealed at one end and then filled with liquid mercury metal .

Where does the reading from a J-tube barometer come from?

“j-tubes” were fitted into wheel or banjo type barometers where the reading is taken from a dial and indicator hand from the front of the instrument. Cistern tubes were fitted into stick barometers and the reading was taken directly from the tube and a corresponding scale.

How does a barometer measure the air pressure?

A barometer is an instrument used to measure the air pressure. Changes in the barometric pressure occur during changes in the weather. These changes can be fast or slow, drastic or subtle. Go to my forcasting page for a guide.

What to do if your barometer has Mercury in it?

If the opening at the top of the barometer tube is large enough, insert either a small plastic or glass tube with the end sealed. This will prevent the mercury from filling the small tube. With the bottom of the tube near the bottom of the air pocket, slowly release pressure, which should be the air from the bubble.

How to calculate pressure with an open tube manometer?

This physics video tutorial provides a basic introduction into the open tube manometer also known as the u-tube manometer. It explains how to calculate the absolute pressure of the gas in the bulb and the gauge pressure given the height difference in the two columns. In addition, it discusses how to calculate the density of the unknown fluid.