Design of A Low Cost Three Dimensional Anemometer Device for Carbon Flux Measurement

Eddy covariance method has been widely used to measure the flux of CO2 gas exchange between ecosystems and the atmosphere, typically employing gas analysers and 3D anemometers. However, the high cost of these devices often limits their widespread application. This research aims to design and build an affordable 3D anemometer using low-cost airspeed sensors. Our main objective is to develop a 3D anemometer device capable of measuring three-dimensional wind speed and direction, and to perform data acquisition for potential use in carbon flux measurements. The research method employed is experimental, involving the design, manufacture, and direct application of the device in a palm oil plantation. We present a novel design using six digital airspeed sensors arranged in a 3D Cartesian coordinate system. The device utilizes an Arduino Portenta H7 microcontroller for data acquisition and Raspberry Pi 5 for data logger and data transmission. The device's design minimizes aerodynamic interference, and the sensors were calibrated to ensure accurate readings. Our results demonstrate the successful construction of a 3D anemometer device with a power consumption of 2.2 Wh, reflecting achievements in both power efficiency and cost-effectiveness. The commissioning test was done for 7 days, in which the device was tested on measuring the speed and direction of carbon flux continuously for 40 minutes in every hours. The system achieved a data acquisition success rate of 99.93%, demonstrating high reliability. Additionally, we present raw data visualizations and discuss the device's ability to measure wind speed and direction in all three dimensions. These findings support the potential application of 3D anemometer devices in understanding and monitoring ecological processes involving changes in carbon dioxide in the environment. Although this initial test focused on raw sensor data, future work will include direct comparisons with state-of-the-art 3D anemometers and demonstration of its application in eddy covariance measurements The results indicate that this low-cost solution holds promise for practical use in environmental monitoring and agricultural applications.