Which device measures the mass flow rate of a fluid?

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Measuring mass flow rate requires a device designed to sense mass passing per unit time, not just how fast the fluid is moving. A mass flow meter does exactly that, often using principles like the Coriolis effect or thermal methods to measure the actual mass flow directly. This direct approach remains accurate even when density changes, which is crucial for processes where density isn’t constant. In contrast, velocity meters only capture fluid speed and would need density and cross-sectional area to convert to mass flow, adding potential error. Ultrasonic meters typically measure volumetric flow by tracking sound-wave transit or reflection; they can infer mass flow if density is known, but they don’t read mass flow directly. Optical meters aren’t used for mass flow measurement. So the device that measures mass flow rate most reliably and directly is the mass flow meter.