The first design of these devices was certainly clever but not without its flaws. Each one of the four hemispherical cups was attached to the end of the wire which was holstered one vertical base. The number of turns it took over a period of time was used to measure the speed of wind over that instance. Soon afterward, the lengths of the arms and the weights of the cups began to emerge as a variable factor for the overall calculation. Against the initial assumption, the lengths of the arms and even the size and weights of the hemispheres affected the overall calculations. This was when work was started to create newer and more comprehensive designs that were more accurate.
This design uses the same concept as the original anemometer, but it comes with a slight change in its design. The windmill, instead of vertical, is mounted horizontally on the mount.
Laser Doppler anemometer
This one uses a different technique and is more complex in its working. A light beam is sent out over a period of time, and then its reflection is recorded to be compared with the original light beam. The created Doppler shift of the particles is used to measure the speed of the wind.
These devices use a wire which is heated beyond the environment’s temperature. The speed with which it cools down will be recorded to measure the speed and resistance of wind.
This one makes uses of ultrasonic waves of sound and uses the same principle as that of a laser Doppler anemometer. This is a preferred choice for people who need the speed of wind for navigation and weather recording purposes on a smaller scale. It is because it is accurate and doesn’t need to be moved a lot.
This is one design we all have come across in our science books as kids. The simplest and earliest of designs created to measure air pressure. It was first invented in 1775 by James Lind and since then has undergone numerous changes. The simplest version uses a u-shaped tube which is filled with a liquid and is exposed to atmospheric temperature. The tube has one end in the vertical position facing the pressure, and the other end has a horizontal opening. The difference in the liquid volume correlates to the atmospheric pressure at that time.
Fast forwarding it to the current times, you now have various designs for anemometers in digital forms. These devices give the results in a digital format and are easy to be interfaced with other equipment. The designs that have been discussed above are useful in many situations but are still prone to flaws. The digital ones are considered to be more reliable and accurate. These handheld anemometers are portable and easy to carry around. This way you get to measure the speed and pressure of the wind in all circumstances accurately without much hassle.