Research on dynamic characteristics of laminar flow meter

To research the dynamic characteristics of Laminar Flow Meter (LFM) on millisecond scale, a test device based on the pVTt gas flow standard device with a high-speed electromagnetic valve for generating unsteady flow is designed. According to the parameters of the device and the predicted characteristics of unsteady flow test, a sheet-type LFM with a range of 10 NL/min is designed, the dynamic characteristics of which under step flow and pulsating flow excitations are researched. The time-domain analysis of LFM output under step flow excitation shows that the delay time is 24.9 ms, the rise time is 29.2 ms, and the adjustment time is 55.3 ms. The results of pulsation flow test show that the LFM can effectively measure the instantaneous flow waveform of pulsating flow and the differences of cumulative flow given by the LFM and the test device are less than ±2 %. This research explores a feasible method to trace the dynamic characteristics of the LFM to the SI units, which provides a very valuable reference for researchers who encounter difficulties in flow measurement of unsteady flow research.