Aiming to difficulties of resolving force existing liquid flowmeter for low flow and micro flow is not enough

design a new type liquid micro flow detect instrument based on principle of double differential pressure.On the other side of the single differential pressure sensor

connected with exactly the same pressure pipe and differential pressure sensor

when liquid flows through catheter

can simultaneously generate pressure difference on both sides of between input tube and output tube

form double differential pressure.Double differential pressure sensor transforms pressure difference between liquid and pipe entrance and exit into voltage output

after amplified by the amplifying circuit sent to single chip to realize A/D conversion and signal processing

and finally show the flow value.Test results show that

resolution of the micro flow detector is up to 0.1 mL/min

reproducibility of each flow point is prior to 0.042 %

and it has advantages of novel design principle

simple structure

high precision

wide measuring range.