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tube is named for Henri Pitot, who invented it in 1732.
Henry Philibert Gaspard Darcy, another Frenchman, published a paper
in 1858 that made improvements on Pitotís invention.
The first patent for the use of a Pitot tube to measure velocity in
pipes was given to Henry Fladd of
Missouri, in 1889.
tubes are of two types:
Multiport averaging Pitot tubes
single port Pitot tube includes an L-shaped tube measuring impact
pressure. This tube is inserted
into the flowstream, with the opening facing directly into the flow.
Another tube measuring static pressure has an opening parallel to
the direction of flow. Flowrate
is proportional to the difference between impact pressure and static
A multiport averaging Pitot tube
has multiple ports to measure impact pressure and static pressure at
different points. The DP
transmitter computes flowrate by taking the average of the differences in
pressure readings at different points.
companies such as Emerson Rosemount and Veris have introduced proprietary
versions of the averaging Pitot tube. Emerson
Rosemountís proprietary version is called the Annubar, and it was
formerly sold by Dieterich Standard, now part of Emerson Process
Management. Verisí averaging
Pitot tube is called the Verabar.
Multiport Averaging Pitot Tube. Photo courtesy of Veris.
further information on differential pressure, including studies and articles,
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