Accurate determination of differential pressure between two pressure balances using a pressure transducer

To determine the differential pressure accurately, the measurement method using a precise pressure transducer and two air-operated constant volume valves is proposed in this paper. The advantages of the proposed methods are as follows: (1) By the usage of two air-operated constant volume valves, the pressure generated by the pressure balance can be connected and disconnected quickly to the transducer without no volume change in the hydraulic circuit and no heat transfer from human body. (2) By managing the time intervals between measurements equally using the program developed, the method proposed can generally remove the effect of the drift component in the successive values measured by the transducer used. (3) The short time stability of the pressure generated by each pressure balance used can be evaluated quantitatively at each pressure. From the measurement results, it was revealed that the differential pressure could be determined accurately using the convenient method proposed, and the differences between this method and the conventional fall-rate method were sufficiently small.