Design and experimental characterization of a gas flow generator to calibrate flow meters for neonatal ventilation

A variable gas flow generator (GFG) for dynamic characterization of flowmeters is described. The GFG is an electromechanical system consisting of a spherical chamber where air, compressed by four cylinder-piston systems, flows through a circular aperture. Experimental data show that the pistons displacement of GFG can accurately follow a sinusoidal waveform up to 22 Hz (RMSE<;0.16 mm). Flow rates generated by the above mentioned displacement waveforms can also be assumed sinusoidal. After the experimental characterization, the GFG is used to assess the frequency response of an orifice meter (OM) designed to be used in neonatal ventilation. Experimental data show that the OM has good dynamic response, being able to detect sinusoidal flow rates up to 22 Hz. With reference to the dynamic response, the ad hoc designed OM satisfies the requirements for measuring flow in neonatal ventilation.