Venturi Flow Meters

go to www.google.com type in this, with quotes and the + in front of venturi.

into the search window

"coefficient of discharge" +venturi

then click search

it will give you over 1100 places to read.

Call the manufacturer with the information about the flowing fluid and use thier recomendation. If the VM is inside its performance range, the quality of the manometer is the best question.

An incorrect value for CD negatively affects the quality of your results. The manufacturer of your Venturi flow meter likely has published CD values for a range of Reynolds number and throat diameters. Another source of information is an ASME publication named FLUID METERS, ISBN number 0-7918-0643-x. It has good information on Venturi meter designs and CD's. A particularly interesting Venturi design is a Herschel type Venturi meter which has the property of having a relatively constant CD over a wide range of Reynolds numbers.

Hope this helps.

The best document to look at is ISO 5167 part III venturi meters it details all the issues with C.d. determination and also about wet calibration

hi

I have ASMe (Fluid Meters) in 131 pages.

if you like to have it send mail to boundarylayer2000@yahoo.com