FAD Meter v/s Orifice Flowmeters
FAD Meter v/s Thermal Massmeters
Features & Technical Specifications
|Forbes Marshall FAD Meter
||Working Principle - based on the development of a Karman vortex-shedding street in the wake of a body built into the pipeline.
The periodic shedding of eddies occurs first from one side and then from the other side of a bluff body (vortex-shedding body) installed perpendicular to the pipe axis. Vortex shedding generates a so-called "Karman vortex street" with alternating pressure conditions whose frequency is proportional to the flow velocity.
|With an orifice plate, the fluid flow is measured through the difference in pressure from the upstream side to the downstream side of a partially obstructed pipe. The plate obstructing the flow offers a precisely measured obstruction that narrows the pipe and forces the flowing fluid to constrict
||Accuracy: ±1% of measured value
||Accuracy: ±3% of measured value
||Pressure & Temperature Compensation: Inbuilt and Online compensation
||Pressure & Temperature Compensation: Pressure compensation not available. Additional pressure & temperature transmitters and flow computer required, further reducing accuracy
||Pressure Drop: Very negligible. Usually < 0.05 bar. Hence reduced energy consumption
||Pressure & Temperature Compensation: Very significant. Usually > 0.2 bar. Hence greater energy consumption
||Reliability: Resistant to damage, wear and tear. No erosion of precision of readings
||Reliability: Any wear and tear causes drop in accuracy of readings.
||Sensor located behind bluff body – safe from dirt and particulate matter carried in air
||Susceptible to damage from dirt and particulate matter from wear and tear