Anemometer

Measure and test environmental fluctuations with our choice of anemometers at Cromwell. Available in a range of sizes and designs, we stock high-performance equipment from market-leading brands, like Oxford®.

What is an anemometer?

Sometimes called a wind speed metre or an air flow speed metre, an anemometer is a device used for measuring wind speed and will sometimes display the wind direction. Some devices are mounted to a roof or pivot point, much like a weathervane, and transmit the measurements to a connected monitoring system. Others are digital, hand-held devices that feature an integrated fan component, or a fan connected on a wire to calculate readings on the move.

Why buy an anemometer?

For industries who require wind speed measurements, an anemometer is an important tool. Measuring wind speed helps to identify changes or patterns in the weather, which supports weather stations and pilots. Elsewhere, engineers who work in the automotive or aerospace industries will use an anemometer to calculate the aerodynamics or a car, or the wind speed generated by an aeroplane.

Anemometer types

Anemometers are available in a wide range of designs to capture the speed and changes to wind, gas, or other particles. Here we've outlines some of the most popular on the market to help you identify the best type for your application...

• Cup anemometers  -   This type features between three to four cups mounted on a pole, which is then attached to a building or other sturdy structure. The cups capture the wind as it blows and spin according to the speed of the wind. The rotations of the cup are captured and calibrated to record wind speed.

• Hot wire anemometers   -   Used locations where the temperature remains constant and to monitor exhausts, this type of anemometer is a unique design. Wire is heated to a set temperature and then exposed to the wind. Air flow is measured according to the speed and to what extent the wire cools.

• Laser doppler anemometers   -   Used to measure the changes and flow of gas, wind and particulate, this type of anemometer uses laser beams and a light detector to identify slight shifts in movement. These are shown in the disturbance or scattering of light and makes for a very precise measurement.

• Ultrasonic anemometers   -   Working under a similar concept of the laser doppler anemometer, this design measures the affect of wind flow on the speed of sound waves sent between two fixed transducers.

• Vane anemometers   -   This type features a fan-type component often called a propeller or windmill design. They measure wind speed in a similar way to cup anemometers, only it's the propeller speed that's calibrated. These anemometers give extremely accurate readings and are available as handheld or mounted variants.

• Windmill anemometers   -   This type of anemometer is similar to the vane variant but is larger and mounted to a roof or other sturdy point. The movement and direction of the propellers is measured during a set timeframe to identify wind flow measurements.

Considerations when choosing an anemometer

• Type - depending on your role, you may need a digital anemometer for both inside and outside use for engineering purposes for example, or an external mounted device may give the best readings for a meteorologist or weather office.

• Metrics - ensure your chosen device displays the unit of measure you wish to log.

• Maximum / minimum measurements - always check the maximum and minimum capacity of a device before you buy to ensure it covers the range you need.

• Size - if you plan to be on the move with your anemometer consider the size and construction required. Is it easy to transport? Will it be too bulky?

FAQs

What units do anemometers measure in?

Most anemometers deliver a feet per minute (FPM) measurement, which highlights the rotation or spin action of the device. However, some digital variants allow for user selection and will display units in metres per second (m/s), kilometres per hour (km/h), feet per minute (ft/min), miles per hour (MPH), a nautical mile (KNOTS), cubic feet per minute (CFM) and coordinate measurements (CMM).

How accurate is an anemometer?

Anemometers must be regularly calibrated to ensure readings are accurate, but even then, accuracy can vary depending on the type of device you're using. A fully calibrated device will deliver measurements within an accuracy of about 2% (depending on type) to prevent miscalculations.