Many of the methods of measuring air speed and pressure may be appropriate for your needs. Some, like hot-wire anemometers, are more sensitive than other methods. Speak to your KWIPPED network supplier to determine which type is best for your needs. Your other main decision will be which size anemometer is best for your project.
Features of anemometers
Anemometers come in a variety of sizes; handheld are popular as are larger models that can be installed permanently or semi-permanently. They all will have one of the methods of measuring the air speed and pressure described in the How Anemometers Work section. There also will be a way for you to gather the measurement readings, frequently a digital display.
How anemometers work
Air speed and pressure are calculated by measuring the changes in different aspects of the anemometer. There are two types, those that measure the velocity of the air and those that measure the pressure. The following lists are the many methods of measuring wind speed and pressure.
- Cup: 3 arms with cups on the ends catch in the wind and spin, the air speed is calculated from the speed of the spinning arms
- Vane: propeller or windmill-like, spinning blades catch in the wind
- Hot-wire: a small wire is heated with electric current, the air speed is calculated from the change in temperature caused by the wind
- Laser Doppler: air speed is calculated from the motion of particles in a light beam
- Sonic: ultrasonic sound wave pulses are sent between transducers, air speed is calculated from the time it takes for the pulses to reach the next transducer
- Acoustic resonance: acoustic waves resonate in a chamber
- Plate: a flat plate faces the wind; pressure is calculated from the compression of a spring behind the plate
- Tube: liquid in tubing allows for pressure to build in one end as wind blows across small holes in the tubing