Which instrument is used to measure mass flow?

• A. Turbine Flow Meter
• B. Ultrasonic Flow Meter
• C. Magnetic Flow Meter
• D. Material Mass Flow Meter

Answer: (D)

Mass flow is how much material passes a point per unit time, regardless of how dense or light the fluid is. The instruments Turbine Flow Meter, Ultrasonic Flow Meter, and Magnetic Flow Meter are all designed to measure how much fluid flows by volume each second, often needing density information to convert that into mass, which can introduce errors if density changes. The device described as a Mass Flow Meter is built to determine mass flow directly, without needing density assumptions. In practice, mass flow meters like those based on Coriolis or thermal principles measure the actual mass flowing through them, providing consistent readings even when fluid density varies. Because the question asks which instrument measures mass flow, the direct mass-flow instrument is the best choice.