In the master's thesis we described an anemometer's development, which must be cheap, without moving parts, easy to manufacture and consume as little energy as possible. The diode was chosen as a measuring element due to the voltage change's linearity as a temperature function.
We used two sensors in the measurement: a reference, used to compensate for the ambient temperature changes, and a measuring one, which was heated and its cooling rate was measured. Each sensor consisted of a pair of diodes connected in series, thus achieving a more considerable voltage change at the same temperature change. We calculated the air flow rate from measurements of the voltage difference between the sensors by calculating the cooling time constant.
The text first describes the different types of anemometers – also, the measurements of the developed anemometer based on the diodes' temperature difference. The following sections present the wind tunnel we designed for the measurements, sensor selection, wiring diagram, and printed circuit board. We then described the control program, sensor reading, and wind speed calculation we developed. Finally, we described the anemometer calibration process and presented the results of experimental measurements.
We have shown that the developed anemometer works, but the measurement with standard, general-purpose diodes has some limitations, such as a long measurement time. Such an anemometer could be useful in all air flow measurements where we can ensure laminar airflow.
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