Which type of flow meter is used to measure the velocity of a conductive fluid?

The magnet flow meter, also known as a magnetic flow meter or magmeter, is specifically designed to measure the velocity of conductive fluids. This type of flow meter operates on Faraday's law of electromagnetic induction, where a magnetic field is applied to the fluid being measured. When a conductive fluid flows through the magnetic field, it induces a voltage proportional to the fluid's velocity. By measuring this induced voltage, the flow meter can accurately determine the flow rate.

This method is particularly effective for fluids that have sufficient electrical conductivity, making it suitable for many industrial applications where typical fluids such as water, acids, and slurries are involved. The design of magnetic flow meters ensures that they provide accurate flow measurements without the need for moving parts, which enhances their durability and reliability in harsh environments.

In contrast, other flow meter types mentioned do not specifically depend on fluid conductivity in the same way. Ultrasonic flow meters rely on the propagation of sound waves in the fluid, positive displacement meters measure flow based on discrete volumes, and Coriolis meters measure mass flow based on changes in fluid momentum. While each has its applications, the magnet flow meter’s unique principles make it the most appropriate choice for conductive fluids.