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Minimum Detectable Air Velocity by Thermal Flow Sensors
IMSAS (Institute for Microsensors, Actuators and Systems), Microsystems Center Bremen (MCB), University of Bremen, Otto-Hahn-Allee, Bld. NW1, Bremen D-28359, Germany
* Author to whom correspondence should be addressed.
Received: 20 June 2013; in revised form: 29 July 2013 / Accepted: 14 August 2013 / Published: 19 August 2013
Abstract: Miniaturized thermal flow sensors have opened the doors for a large variety of new applications due to their small size, high sensitivity and low power consumption. Theoretically, very small detection limits of air velocity of some micrometers per second are achievable. However, the superimposed free convection is the main obstacle which prevents reaching these expected limits. Furthermore, experimental investigations are an additional challenge since it is difficult to generate very low flows. In this paper, we introduce a physical method, capable of generating very low flow values in the mixed convection region. Additionally, we present the sensor characteristic curves at the zero flow case and in the mixed convection region. Results show that the estimated minimum detectable air velocity by the presented method is 0.8 mm/s. The equivalent air velocity to the noise level of the sensor at the zero flow case is about 0.13 mm/s.
Keywords: minimum detectable flow; natural convection; noise; mixed convection region; thermal flow sensors
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MDPI and ACS Style
Issa, S.; Lang, W. Minimum Detectable Air Velocity by Thermal Flow Sensors. Sensors 2013, 13, 10944-10953.
Issa S, Lang W. Minimum Detectable Air Velocity by Thermal Flow Sensors. Sensors. 2013; 13(8):10944-10953.
Issa, Safir; Lang, Walter. 2013. "Minimum Detectable Air Velocity by Thermal Flow Sensors." Sensors 13, no. 8: 10944-10953.