Talk:FlowSensors

From ControlsWiki

1) Propeller Flow Meter

Propeller flow meters have a rotating element similar to the wheel in turbine meters. Again, rotation is caused by fluid flow through the propeller, and voltage pulses are created as the propeller passes a magnetic or optical sensor. Similarly, the frequency of the pulses is proportional to flow rate of the fluid and the voltages can be directly correlated with the fluid flow rate.

How are propeller flow meters different from turbine meters? Looking at the pictures I can't tell, and the text doesn't explain either.

2) What is meant by "clean" liquids? Low concentration of solid particulates?

3) Conic-edge orifice offset from center of plate?

In the description of the conic-edge orifice plate, the article states that the difference between a square-edge plate and a conic-edge plate is that "the opening is offset from the pipe’s center." This description is misleading, and may cause the reader to believe that the orifice in this case is not at the center of the pipe but to the right or left of the center. A better description may be: The conic-edge orifice is similar to the square-edge orifice, however, the conic-edge orifice does not have a constant cross-sectional area but a gradually contracting or expanding one. The cross-sectional area expands, as would the cross-sectional area of a conic from one height to another along the edge. The conic-edge geometry has the advantage of maintaining a more constant discharge coefficient at low Reynolds numbers because of the special geometry but is used mostly in Europe.