Annubar

An annubar is similar to a pitot tube used to measure the flow of gas or liquid in a pipe.

The pitot tube measures the difference between the static pressure and the flowing pressure of the media in the pipe. The volumetric flow is calculated from that difference using Bernoulli's principle and taking into account the pipe inside diameter. [Perry, Robert H., Don W. Green. "Perry's Chemical Engineer's Handbook, Seventh Edition". pages 10-8 to 10-9. McGraw Hill. 1997]

The biggest difference between an annubar and a pitot tube is that an annubar takes multiple samples across a section of a pipe or duct. In this way, the annubar averages the differential pressures encountered accounting for variations in flow across the section. A pitot tube will give a similar reading if the tip is located at a point in the pipe cross section where the flowing velocity is close to the average velocity.

Annubar is a registered trade name with Emerson Process Management / Rosemount. [ [http://www.emersonprocess.com/rosemount/products/flow/m285annubar.html Rosemount 285 Annubar® Primary Element Series ] ]

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