Self Heated Thermo-Resistive Element Hot Wire Anemometer

Sch. of Eng., Griffith Univ., Gold Coast, QLD, Australia
IEEE Sensors Journal (Impact Factor: 1.76). 05/2010; 10(4):847 - 848. DOI: 10.1109/JSEN.2009.2035518
Source: IEEE Xplore


A microelectromechanical systems (MEMS) hot wire anemometer consisting of thermoresistive elements arranged in a differential bridge configuration is presented. The excitation of the elements to the point of self heating allows for dedicated heating elements to be omitted from the device without compromising operation or accuracy. Overall power consumption gives air velocity, and the temperature differential of each element pair is used for wind direction calculation and has demonstrated a sensing resolution better than 1% and a repeatability better than 2%.

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    • "The first uses the front surface of the sensor to sense the wind [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]. In these thermal wind sensors, the heaters and sensing parts are placed on micromembranes and bridges to minimize the heat loss through the substrate [10] [11] [12] [13] [14] [15], whereas others use substrates with low thermal conductivity (i.e. glass [16], porous silicon [17] [18], SU-8 [19], and polyimide [20]) to fabricate the devices. "
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    • "using microfabrication techniques to produce miniaturized, low cost, high-performance devices for wind sensing applications. In 2003, Adamec et al. [23], [24] presented a multiaxis HWA fabricated with bulk micromachining and thin film semiconductor technologies. The proposed anemometer consists of thermoresistive elements arranged in a differential bridge configuration, as shown in Fig. 4(b). "
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