| In recent years,through continuous practice,scholars of flow measurement have invented a very practical and stable metering standard device,namely,the sonic nozzle metering standard device.Although a more practical standard device has been explored,how to realize the accurate verification of the gas flowmeter,and in the verification process,reduce the factors that affect the verification accuracy,to provide technical support and theoretical support for enterprise production.In this paper,the sonic nozzle method standard instrument is adopted to verify the gas flowmeter through test.The main research contents include:Firstly,the theoretical basis of the standard gas flow device based on the sonic nozzle method is summarized,and the workflow of the device is explained.Secondly,the repeatability and stability of the device were tested and verified,and then the operation of the test device was summarized.Three kinds of gas flow meters were tested and tested.The test proved that the standard device of sonic nozzle method could complete the test of the flow meter,and the data was analyzed.The factors affecting the device(temperature,pressure,humidity,outflow coefficient and critical back-pressure ratio)were analyzed,which provided technical support for the accuracy verification of the flowmeter.In the end,the uncertainty of measurement results of flow indication error at test points of gas waist wheel flowmeter,gas turbine flowmeter and gas ultrasonic flowmeter is evaluated.The evaluation results are as follows:the extended uncertainty of flowmeter is Ur=0.32%,k=2. |
