Establishment of micro liquid flow facility at NIM

•Establish a micro liquid flow facility based on dynamic weighing method, with the flow rate range of 100nL/min–150 mL/min.•An acquisition method of weighing value based on the fluctuation frequency is adopted to effectively reduce the uncertainty introduced by dynamic reading.•A ‘dual time’ method is used to realize the synchronization between weighing system and meter under test by the “time stamp” with resolution of 1 ms.•The uncertainty sources of balance that came from weighing accuracy of mg magnitude, short-term drift and long-term stability are evaluated by experimental method.•Micro flow facilities have different magnitude uncertainties at different flow rates, and the uncertainty decreases significantly with the increase of flow rates. Another characteristic is that the contribution ratio of the principal uncertainty varies greatly at different typical flow rates.