Preso^® differential pressure flow meters type Ellipse^® model AHF

Due to the conical design of the venturi tubes, the flow of a fluid (gas, water, air) at the narrowest point of the low-pressure (p2 = dynamic pressure) results in the accumulation of the medium and at the outlet of the constriction the highest pressure is forming (p1 = static pressure). The pressure difference (incompressible, without friction) for liquids generated by the Bernoulli equation.

Pitot tubes also work on the basics of the Bernoulli equation. In contrast to the venturi tube, work is done with the help of a second tube which is oriented parallel to the flow of the medium, such that the flow impinging on a front pipe opening. In front of the tube is formed the dynamic pressure, behind the tube, the static pressure. This remains constant.

By different shaped pipe openings, measurement results can be affected. By the elliptical shape of the shaft, lowest permanent pressure loss (type Ellipse^®) is achieved. In contrast trapezoidal pipe openings create strong vortex shedding in the measuring body and thus impede the flow, resulting in a very high flow resistance. All devices can be used both vertically and horizontally.