What are the working principles of speed measuring tube, orifice plate flowmeter and rotary flow meter?
The measuring principle of uniform tube flowmeter: uniform tube flow sensor probe is provided in accordance with certain rules many to take pressure hole (usually 3 pairs), each point on the axis of pipe fluid pressure were measured at the front (upstream direction) measured fluid multi-point full pressure high pressure mean value P1 (including the dynamic pressure of each point is also called the velocity pressure and average static pressure); pressure hole on the side wall of the measured fluid multi-point average static pressure is low average value of P2.P1-P2= P in the low pressure area, so the delta P reflects the average speed of the pressure fluid, namely average velocity size, which can be used to to calculate the fluid flow.
The measuring principle of orifice flowmeter: the fluid filled pipe through the throttling device in the pipeline, causing local contraction, near the throttle velocity increase, static pressure difference in the upper and lower sides. The pressure difference by differential pressure transmitter into traffic.
The measuring principle of rotor flowmeter is a kind of variable area flowmeter, which is composed of a conical tube and a conical tube can be placed on the rotor free movement of upper and lower (also called float). Rotor flowmeter ontology can be used at both ends of flange, thread or hose and measuring pipeline connected vertically installed in the pipeline measurement when the fluid flows into the conical tube. From the bottom to the top, by the rotor closure, the pressure difference is generated between the rotor so that the upper and the lower, the rise of rotor under the action of the pressure difference, then acting on the rotor three forces: fluid dynamic pressure on the rotor, the rotor in the fluid force and the gravity of the rotor.
