1. The composition of differential pressure flow meter: throttling device + pressure conduit + DP transmitter
2. Classification of differential pressure throttling elements: orifice plate, nozzle, venturi, averaging pitot tube, wedge, Verabar, Annubar.
3. Working principle of differential pressure flow meter:
When the fluid is flowing pass the throttling device in the pipeline, the flow rate will locally shrink at the throttle element, so the flow rate increases, static pressure decreases.
According to Bernoulli’s law of conservation of energy, the kinetic energy increases, the potential energy decreases, the positive and negative gravitational potential energy counteracts, and the pressure potential energy decreases, so the differential pressure is generated at the throttle element. The larger the flow rate is, the greater the differential pressure generated, the flow rate can be measured according to the differential pressure.
4. About Differential pressure flow meter, the formula which must be familiar with as follow:
P1 / P2 = Output current I 1 / Output current I 2 = (Q1 / Q2) ^2