What instrument is used for measuring velocity?

Answer 1

A Barometer
The barometer measures air pressure, and the anemometer measures air speed. A wind vane tells the winds direction.
A barometer measures air pressure. I think that's what you meant to say.

An anonometer measures wind speed. A Vane is used to measure wind direction.
It would depend which property of air you were measuring.

Answer 2

• Anemometers measure air velocity. The spinning cups of a weather station are a typical application.
• Air velocity can also be measured using a pitot tube connected to a gauge that measures pressure. That is the basis for an airplane's air speed indicator.
• Air velocity can also be measured using a pressure gauge at a venturi. The faster a fluid moves through a venturi, the lower its pressure. It may sound strange but, air is considered to be a fluid.
• A hot wire is cooled by moving air. If you know the temperature of the wire you can relate the temperature to the air velocity and thereby know how fast the air is moving in a duct. This sort of device is known as a "Hot wire anemometer". For a picture, search for "TSI Velocicalc".
• A Baseball pitcher may drop a handful of dirt or grass to gauge the velocity and direction of the wind. A wind sock serves a similar purpose. Neither of these methods gives a numerical value but, can allow a person to compare the wind to previously observed conditions.

Answer 3

The instrument that is used to measure air pollution is a Barometer.

Answer 4

An anemometer.

Answer 5

barometer