Air velocity meters, commonly called anemometers, are used to measure the speed and/or volume of air movement. Typically, anemometers are used with weather stations to determine the speed of wind.
However, anemometers are also critical instruments for applications such as balancing forced hot air HVAC systems, the analysis of ventilation systems, aerodynamics testing, and fume hood verification.
In fact, any application in which the movement of air is a primary concern can benefit from a quality anemometer.
There are a number of technologies used with modern anemometers:
Vane: Uses a vertically mounted propeller. As the air moves past the propeller it rotates at a speed proportional to wind speed. Vane anemometers measure airflow independent of the air
density making them ideal for many applications where measurement without the need for corrections is desired. Vane anemometers must be held into the direction of airflow to work properly.
Cup: Consists of cups mounted at equal angles on horizontal arms. As with vane anemometers, the cups rotate at a speed proportional to wind speed. The air, no matter the direction
it's moving, always faces into one of the cups rotating eliminating the need to face into the wind.
Hot Wire: Hot wire anemometers use a very fine wire electrically heated up to some temperature above the ambient. Air flowing past the wire has a cooling effect on the wire. As flow
increases, the electrical current must also increase to maintain the temperature of the element. The current is proportional to an output voltage sent to a meter or display. Hot wire type sensors are
better at low airflow measurements than other technologies, and are commonly applied to air velocities below 100 feet per minute because of their sensitivity. Hot wire anemometers require corrections
for high accuracy measurements.
Differential Pressure: Differential pressure anemometers use a pitot tube to direct air flow to a precision pressure measuring instrument (manometer). The flow of air creates pressure
which is detected by the manometer and converted into units of wind speed. The pitot tube must be inserted correctly for accurate velocity measurements.
Anemometers are often combined with other technologies, such as temperature and humidity sensors, to increase the instrument's versatility. Other anemometers, designed for HVAC applications, may include
air capture hoods to isolate air emerging from vents and registers.
As with many modern instruments, some anemometers include advanced features and functions such as data logging and communications which allow data to be stored on the instrument or shared with computers
for reports and graphic representation.
Common uses for anemometers:
- HVAC installation, repair, diagnostics, and optimization
- Fume hood testing, installation, and verification
- Ventilation system installation, servicing, and analysis
- Environmental wind and temperature testing/analysis
- Boiler rooms
- Ionizer flow output monitoring
- Automobile aerodynamic testing
- Plant/facilities maintenance
If you have any questions regarding air velocity meters / anemometers please don't hesitate to speak with one of our engineers by e-mailing us at sales@instrumart.com or calling 1-800-884-4967.
