Using orifice plate is one of the most common methods of measuring flow with differential pressure transmitters. The most common type of orifice plate is a thin plate with a hole in it which is installed in a perpendicular position towards the flow’s path. When fluid pass the orifice plate, because of the decrease in cross section, its speed increases, its pressure drops and as a result, differential pressure occurs between two sides of the plate.
Differential pressure transmitters measure this differential pressure and it helps flowmeters to calculate the flow rate.
This company offer flow element with General Instrument Consortium Brand.