Abstract
In this paper an alternative method for obtaining the sonic conductance and the critical pressure ratio is presented. The proposed method uses an isothermal chamber that can almost realize isothermal condition by stuffing metal wire in the chamber to produce a larger heat transfer area and heat transfer coefficient. Using this chamber, the sonic conductance and the critical pressure ratio is obtained by measuring only pressure in the chamber. And the proposed method is completed in a shorter time and consumes less energy than the ISO 6358 procedure. Furthermore, the authors have investigated the effect of supply pressure change and temperature change in the isothermal chamber. It became clear from the experiment that the proposed method can measure the sonic conductance within 3% error margin and the temperature change counteracts the effects of the supply pressure change.
