Abstract:
To address the challenge of measuring pulsatile microflow under high-pressure conditions in the realm of physical and chemical analysis instrumentation, a methodology grounded on the Hagen-Poiseuille law has been devised. This methodology leverages the differential pressure signal for indirect measurement, capitalizing on the traits of high pressure endurance and swift response manifested by the differential pressure transducer. A scheme for measuring differential pressure values within the pulsatile flow pathway has been designed. Employing numerical integration alongside dual time correction, the accumulated mass derived from differential pressure signals was juxtaposed against the static accumulated mass from a balance to validate the measurement accuracy. This effectively ameliorates the erstwhile issue of low accuracy found in balance weighing and stopwatch timing methods. The differential method’s instantaneous flow rate was corroborated through dynamic sampling functions of a balance. Data outcomes denote that within the pulsatile characteristic range of 0.2 to 0.5 mL/min, the error in measuring average flow rate via the differential method does not exceed ±0.5%, and the error in measuring instantaneous flow rate does not surpass ±1.5%. This accords with the flow measurement accuracy requisites of relevant instruments, and concurrently mitigates the issues of exorbitant pricing of microflow sensors and limited pressure resistance during usage.