Design of displacement gas flow standard equipment

WANG Rui-gang1， ZHAO Jin-yan1， HU Bo2， HUANG Yong2
（1. College of Foundation and Information Engineering， Yunnan Agricultural University， Kunming 650201， China；
2. Yunnan Institute of Measurement and Testing Technology， Kunming 650228， China）

Abstract： The measurement of gas flow is an important part of scientific measurement. Aiming at the problems that the standard equipment at present is adapted lower accuracy and higher cost to the calibration for small gas flow measurement，it is difficult to be realized gas flow verification and calibrated for high precision. According to the basic principle fluid mechanics，the standard method for the detection of gas flow was designed by using liquid displacement method. When the liquid was flowed into the standard measure，it was measured liquid flow into the standard containers，and compared the value with showing for the flow gauge，so it could be detected the gas flow meter accuracy. The experiments were carried out in the preparation of the prototype. Test results indicate that this method could make the expansion uncertainty reach 0.09%，and the calibration accuracy reach 0.2 for the equipment，which could reach the design requirements. The gas flow standard equipment has the advantages of convenient operation，high stability，good repeatability，especially with great advantages in high accuracy for small gas flow measurement.
Key words： measurement of gas flow； flow calibration； replacement； high accuracy