Editing Flow measurement (section)

===Venturi meter===
A [[Venturi effect|Venturi meter]] constricts the flow in some fashion, and [[pressure sensor]]s measure the differential pressure before and within the constriction. This method is widely used to measure flow rate in the transmission of gas through [[Pipeline transport|pipelines]], and has been used since [[Roman Empire]] times. The [[Discharge coefficient|coefficient of discharge]] of Venturi meter ranges from 0.93 to 0.97. The first large-scale Venturi meters to measure liquid flows were developed by [[Clemens Herschel]], who used them to measure small and large flows of water and [[wastewater]] beginning at the very end of the 19th century.<ref>[[Clemens Herschel|Herschel, Clemens]]. (1898). ''Measuring Water''. [[Providence, Rhode Island]]: Builders Iron Foundry.</ref>