Hot Wire Sensor-Based Data Acquisition System for Controlling the Laminar Boundary Layer Near Plant Leaves Within a Greenhouse

摘要

Monitoring a greenhouse needs frequent measurements of inside wind speed, temperature, and moisture. The best growing conditions for cultures are then reached by irrigating them properly. However, the resulting excess of humidity also favors the proliferation of small beasts that cause cryptogrammetric diseases. Instead of using fungicides to destroy them, an ecological approach is implemented, where the boundary layer near the plant leaves is modeled. It consists in reducing the thickness of laminar boundary layer to only a few millimeters, so that the parasite population is rarefied. To experiment such a solution, a data acquisition system equipped with hot wire silicon sensors is implemented so as to control the air ventilation over the plant leaves. These sensors were built using the microelectromechanical system technology and employed to automatically measure humidity, temperature, and wind speed near the plants within the greenhouse. Such sensors, which are very small (100 ), do not disturb the measurements. Thanks to such a system, the air ventilation is suitably controlled and the boundary layer thickness, minimized near the plant leaves.