After three years of research, the National Institute of Quality Supervision, Inspection and Quarantine (AQSIQ) project "Standard for Gas Displacement Gas Flow Rate Devices" undertaken by the Yunnan Metrology Institute has recently been developed.

At present, the Institute has completed the installation and commissioning of equipment and experimental work, the various technical indicators have reached the requirements of the scientific research task book, the successful development of the device will improve the overall level of China's small and medium gas flow measurement, at the same time, for our country's independent innovation of gas flow meter R & D capabilities provide technical support.

According to reports, the scientific research personnel of the Yunnan Provincial Metrology Institute explored the problems existing in the verification process of small and medium gas flowmeters in the daily verification/calibration work, and developed a simple device to conduct theoretical and methodological research. In 2006, a pre-research article on the establishment of "Replacement Method for Gas Flow Standard Devices" was presented at the National Academic Exchange Conference on Flow Tests. Scientific verification methods and models were obtained through previous theoretical methods. In 2008, the institute proposed a scientific research project developed by the "liquid replacement gas flow standard device" to the AQSIQ and obtained project approval from the General Administration of Customs. In the same year, the “Gas Flow Device Test Device” obtained a national utility model patent certificate (Patent No. ZL2007 2 0105236.7).

After unremitting efforts by the scientific staff of the hospital, in November 2010, the device reached the predetermined technical requirements, and achieved automatic collection and control of liquid level, temperature, humidity, pressure, time, and quality. The automatic collection can automatically perform static verification and dynamic verification, and the verification data is automatically stored in the database. The accuracy of the whole device is up to 0.2 (0.05 can be achieved after replacing some equipment and improving environmental conditions). The gas flow measurement range is: (0.1-250)L/min, and the range ratio is as high as 2500:1, which is the first in China. "Liquid displacement gas flow standard device" traces the gas flow volume value to an accurate and reliable mass value, improves the accuracy and reliability of gas flow meter verification/calibration, overcomes the problem of gas flow stability control, and satisfies the The requirements for the precise detection of small and medium gas flows in social and economic construction.