125680-01 Bently Nevada Proximity I/O Module

The voltage sensing electronic circuit in question possesses an extremely high input impedance. For there to be a notable impact on flow measurement accuracy, the equivalent resistance of the liquid would have to be significantly greater than demonstrated in this instance. Actually, fluid conductivity only becomes a factor for a magnetic flowmeter when the fluid’s conductivity can be disregarded. The fluids consist of deionised water (such as steam boiler feedwater and ultrapure water for pharmaceutical and semiconductor manufacturing) and oil. Magnetic flowmeters perform well with most aqueous fluids.

The upstream straight pipe must be 5 diameters and the downstream straight pipe must be 3 diameters. Furthermore, the expansive aperture of the magnetic flow meter tube ensures unobstructed flow and thus minimal permanent pressure loss. With no impediments to fluid flow, the magnetic flow meter can tolerate solids within the stream of process fluids, including wastewater, slurry, wood pulp, and foodstuffs. This tolerance sets it apart from other flow meters that may become clogged under similar circumstances. Magnetic flowmeters are the predominant flowmeter technology in the wastewater, wood pulp, and food processing industries.

125680-01 Conductive liquids must meet a minimum value requirement, but that’s all. Some technicians may be surprised to learn that changes in liquid conductivity have little impact on flow measurement accuracy. However, this doesn’t imply that doubling the liquid conductivity will double the induced voltage! Rather, the electromotive force is determined by physical dimensions, magnetic field strength, and fluid velocity. In voltage measurement circuits, poorly conducting fluids have greater resistance than well conducting fluids, but this result is not significant due to the significantly higher input impedance of the detection circuit!