title: Extrapolation of Calibration Curve of Hot-wire Spirometer Using a Novel Neural Network Based Approach.
abstract: Hot-wire spirometer is a kind of constant temperature anemometer (CTA). The working principle of CTA, used for the measurement of fluid velocity and flow turbulence, is based on convective heat transfer from a hot-wire sensor to a fluid being measured. The calibration curve of a CTA is nonlinear and cannot be easily extrapolated beyond its calibration range. Therefore, a method for extrapolation of CTA calibration curve will be of great practical application. In this paper, a novel approach based on the conventional neural network and self-organizing map (SOM) method has been proposed to extrapolate CTA calibration curve for measurement of velocity in the range 0.7-30 m/seconds. Results show that, using this approach for the extrapolation of the CTA calibration curve beyond its upper limit, the standard deviation is about -0.5%, which is acceptable in most cases. Moreover, this approach for the extrapolation of the CTA calibration curve below its lower limit produces standard deviation of about 4.5%, which is acceptable in spirometry applications. Finally, the standard deviation on the whole measurement range (0.7-30 m/s) is about 1.5%.
authors.affiliation: Department of Mechanical Engineering, Iranian Research Organization for Science and Technology, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Ardekani
authors.forename: Vahid Reza
authors.initials: VR
authors.lastname: Nafisi
authors.forename: Foad
authors.initials: F
authors.lastname: Farhani
keywords: Calibration curve; hot-wire spirometer; neural network curve fitting; self-organizing map