STUDY ON MEASUREMENT METHOD OF SMALL ORIFICE CONDUCTANCE

Two methods of measuring conductance are introduced under the condition of molecular flow,namely,with constant volume method and constant pressure method.The measurement uncertainty is also analyzed.The small orifice conductance is measured with calibration apparatus of constant volume and calibration apparatus of constant pressure.The comparison of two measurement methods are done.The two agree fairly well,the difference is less than 1.0%.