Aerospace Science and Technology Research Center,National Cheng-Kung University - Flow Measurement Laboratory

To most people, "flow measurement" is an idea that is both familiar and unfamiliar. We are familiar with routine fuel and water costs, and we know that the amount due is measured by a flow meter: a common device of our everyday lives. Although most people feel that the details are too difficult to understand, flow measurement is really important in both our daily lives and in industry.

In order to ensure flow measurement accuracy, it's important to meet the regulations and standards determined by the national government of Taiwan. Therefore, flowmeters need calibrating regularly to trace to the national standards directly or indirectly.

In the early 1990's, the national standard of flow measurement was provided by the national standard flow laboratory, NMI. However, for gas flow calibration, the maximum flow rate offered by NMI is 2 kg/s. This is not sufficient for the needs of the petrochemical industry, which requires a high flow rate. To accommodate this need, NMI sought a partner institution to cooperate in having more powerful calibration equipment in order to combine with the national standard flow laboratory and create a comprehensive and standard flow certification system.

Our laboratory at the Aerospace Science and Technology Research Center of National Cheng Kung University became this partner institution in 2000. This laboratory has a high pressure gas tank capacity for 6400 ft3. At 750psi, these tanks can sustain a flow rate of 10kg/s for up to 12 minutes through the 6'' pipe system. The standard flow systems in FML use sonic nozzles as standard meters, covering a range from 10~2.4×104m3/hr (SCMH). From 2001, this system started to offer service for gas meter calibration and testing. These capabilities complement the equipment and abilities of the national laboratory in providing a full standardized certification process for flow meters.

At almost the same time, FML helped the Bureau of Standards build up the regulations for gas diaphragm meter pattern approval and was assigned to implement the regulations. Therefore, in 2002 FML set up another standard flow system with a flow rate that ranges from 0.012~180 m³/hr (SCMH). Since 2004, a total of more than 100 gas diaphragm meter patterns of have been approved

From 2011 to 2012, the Bureau of Standards wanted to check the accuracy of the calibration facilities for diaphragm meters. These facilities, which were located in different places throughout Taiwan, belonged to different laboratories, companies, and the Bureau of Standards. Therefore, a project was created in order to compare flow measurement results between labs. FML was in charge of the project and also played the role of central laboratory. A total of 14 sets of facilities were compared.

In 2001, FML was also commissioned by Taiwan Water Corporation as the designated laboratory for performing air-venting valve testing for pipe diameters from 1 "to 8."