A metrological traceability system for microflowrate measurement

Applications of MEMS have prompted the design and manufacture of fluidic devices for sub-microliter fluid flow measurement. The accuracy of flowrate in terms of traceability and repeatability provides key information for successful micro-fluidics applications. To establish a measurement standard for microflow sensors and microflow controller for liquid handling and microfluidic monitoring, a traceable measurement system at Taiwan's NMI has been sponsoring since 2002. The applied approaches included a gravimetric approach, a virtual piston approach, and a velocity-based approach. The expected flowrate ranges from 10 mL/min down to 10 nL/min, and the measurement uncertainty is evaluated. In this paper, the gravimetric approach and the chip based volumetric approach were demonstrated of their measurement setup and capability.