The working principle is that when there is horizontal wind in the environment, the special structure of the wind cup produce a certain direction of rotation, driving the built-in sensor to generate voltage, which is proportional to the rotation speed. The change of this signal voltage is displayed by connecting to a specially customized pointer instrument. This sensor is spontaneous and does not require power. When there is wind rotation, a voltage signal is generated and displayed by the meter. This wind speed sensor has a simple structure and general accuracy. It is only suitable for environmental wind speed reference and not for weather forecast applications., Weight: 0.31526103466 pounds, Manufacturer: Duanthry