Electromagnetic flow meters operate on Faraday's law of electromagnetic induction, which states that a voltage is induced when a conductor moves through a magnetic field. The liquid serves as the conductor; the magnetic field is created by energized coils outside the flow tube. When selecting electromagnetic flow meters, parameters include pipe diameter, mounting type, end fittings, performance specifications, output options, and special features. The ability to meter liquids with suspended solids (slurries) and monitor media temperature are also important considerations.