A Silicon-Based Combined Hot-Element and Calorimetric Anemometer

A micro-fabricated silicon-based anemometer has been improved by employing a differential calorimetric measurement technique, while additional sensing information is extracted from the constant temperature heater. This combination improves the measurement range, as established experimentally and supported by finite element simulations. The straight-forward three mask fabrication process is also presented. The use of a lock-in amplifier to read out the sensing elements also provides additional information on the wind direction contained in the phase shift. With this information and theoretical basis, the combined anemometer leads to an increased measurement range and an improved <1% full-scale precision.