Using Magnetic flowmeters for slurry flow can be a tricky thing as the relationship between the flow velocity and the induced voltage is not always exactly proportional. Depending on the slurries types, the resulting noise could present a major challenge causing some to give up on magnetic flowmeter when face with slurry flow.
Experienced operators when measuring slurry flow using magnetic meters, will sometimes increase the signal damping to overcome the resulting process noise which is causing unstable or noisy readings. Signal damping is simple and is easy to implement but it may not be an ideal solution as it masks actual process changes.
In our experience, operators can often be left wondering why, after increasing the signal damping, they are still unable to optimise their process control. I've found this application note on an actual case to be quite useful, especially since it provides data on the effects process noise on magnetic meters, comparing the situations before and after the solution implementation. Basically, the customer utilized the Rosemount magnetic flowmeter’s adjustable coil frequency capability to effectively sidestep the noise from the process.
Are the pipes getting noisy as well in your plant?”