Principles and features of differential pressure flow meters
Various types of flow meters and flow sensors are available. This section summarizes the principles and features of differential pressure flow meters.
Differential pressure flow meters currently have the top market share for flow meter production volume. Using Bernoulli's principle, an orifice plate is installed into the path of flowing fluid, deliberately causing pressure loss. The pressure differential before and after the orifice plate is measured. The relationship between the pressure loss generated by the orifice plate , the flow velocity, and the flow rate are as follows:
Small flow ⇒ small flow velocity ⇒ The pressure loss created by the orifice plate is small Large flow ⇒ large flow velocity ⇒ The pressure loss created by the orifice plate is large |
The difference in pressure between upstream and downstream is detected using a pressure diaphragm.
DIFFERENTIAL PRESSURE FLOW METER
PROS | ・Able to detect gases, liquids, and vapors ・Generally low priced ・No moving parts. |
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CONS | ・Because there is an orifice plate, great pressure loss occurs ・Not suited for fluids that include solids (clogging occurs) ・Because it is sensitive to turbulent flow, a long section of straight pipe is required |
CHAPTER 2
FLOW METER TYPES & PRINCIPLES
CHAPTER 2
FLOW METER TYPES & PRINCIPLES