Electromagnetic flow measurement: which statements about a magnetic flowmeter are correct?

Introduction / Context:
Magnetic flowmeters (magmeters) are common for conductive liquids, including corrosive solutions and slurries. They have no intruding elements, minimizing pressure drop and fouling—key advantages in chemical and wastewater processes.

Given Data / Assumptions:

• Conductive fluid with sufficient conductivity (typically > ~5 μS/cm).
• Uniform magnetic field applied across the pipe; electrodes sense induced EMF.
• Flow profile is fully developed or adequately averaged by electrode placement.

Concept / Approach:
Faraday’s law: E = B * L * v, where E is induced voltage, B magnetic flux density, L electrode spacing (pipe diameter), and v average fluid velocity. Because E ∝ v, volumetric flow rate Q = v * A maps linearly to EMF. Absence of moving parts allows handling slurries/electrolytes.

Step-by-Step Solution:
Apply magnetic field across conductive fluid.Moving charges in the fluid induce EMF proportional to velocity.Electrodes pick up voltage; transmitter converts to flow signal.

Verification / Alternative check:
Calibration with known flow (prover or weigh tank) confirms linearity; diagnostics check electrode coating and conductivity thresholds.

Why Other Options Are Wrong:
Each individual statement is accurate; the comprehensive choice correctly groups them.

Common Pitfalls:
Using magmeters for non-conductive fluids (e.g., hydrocarbons) yields no signal; electrode coating or air entrainment causes noise.

Final Answer:
All of (a), (b), and (c)