Flow Measurement

Sorry but no. You need to use flow differential calculations to arrive at a correct diff to calibrate the DP cell to. If you want to do it without calcs, measure the diff across the orifice at max flow and that will be the DP Cell calibration 100% figure, it may be only 20kPa when the line pressure could be 6000kPa.

Rok

Differential-pressure-across-an-orifice is so 1972.

Why not use a vortex-shedding meter instead, with all the features and a linear 4-20mA signal 2-wire capability built in, perhaps?

Calibrate the DP with a stand pipe or two.

Pick your range...calibrate your tx...and size your plate according to the flow.

try turbinemeter /rotameter, why dp cell ?

DP cells are cheap, "Vortex Shredding" flow meters are not. Alot of companies are cheap, ie. the one I work for. Therfore you'll find alot of DPs kicking around.

typo sorry "Shedding"

If you know the pipe ID and the Orifice size, you can use a program to predict the DP.

if this is a liquid application it easy, if gas, pressure and gas compostion is needed.\

you can obtain a decent calculation program by going to this link, free and they are one of the oldest suppliers of orifice meters.

http://www.emersonprocess.com/daniel/Products/gas/orifice/orifice_flow_cal.asp