Measuring principle of differential-pressure flowmeters
Orifice plates, nozzles and Venturi tubes
This kind of differential-pressure flowmeters contain an artificial constriction (e.g. an orifice, a nozzle or a Venturi tube). As soon as the fluid starts flowing, the natural laws governing the mechanics of flow dictate that pressure upstream of the constriction increases, only to drop again immediately downstream of the constriction. The pressure differential is a direct measure of the flow rate.
This method uses a rod-like primary element. Pressure tappings are located on the front and rear of this probe. The upstream tappings register dynamic and static pressure, the downstream tappings register only static pressure. The differential pressure is a direct measure for the flow rate.
Time proven robust technique
Wide range of line sizes
No process interruption for exchanging transmitters
Broad choice of materials
Ceramic, self-checking sensor
Wide temperature and pressure range
Very high repeatability