What Is a Flowmeter?

Sales of Various Flow Meters

A flowmeter or flow sensor works by measuring the amount of liquid, gas, or vapor passing through flow sensors. It measures the linear flow, non-linear flow, mass flow, or volumetric flow of a liquid or gas.

Types of Flowmeters

Types of flowmeters include:

• Turbine Flowmeter

• Ultrasonic Flowmeter

• Vortex Flowmeter

• Vortex Flowmeter

• Orifice Plate Flowmeter

• Coriolis Flowmeter

• Thermal Mass Flowmeter

• Pitot Flowmeter

• Rotameter Flowmeter

• Magnetic Flowmeter

• Pressure Differential Flowmeter

Flowmeter Measurement Range

To determine the measurement range of flow measured by a flowmeter, the minimum and maximum flow rates (mass flow or volumetric flow) and the required flow measurement accuracy must be determined. Typically, accuracy is expressed as a percentage of actual reading (AR), percentage of calibrated span (CS), or percentage of full-scale units (FS). The measurement accuracy should be specified at a minimum, normal, and maximum flow to ensure that the flowmeter performs acceptably across the entire range.

In some applications, accuracy is more critical, while in others, repeatability is of greater importance, and the accuracy and repeatability of each process must be examined individually.

When the accuracy of a flowmeter is expressed in terms of % AR or % FS, the absolute error increases as the measured flow rate decreases. If the error is expressed in terms of % CS, it remains constant for low or high flow rates. Since full scale (FS) is always greater than calibrated span (CS), a sensor with a % FS performance always has a larger error than a sensor with % CS specifications. Therefore, for accurate comparisons, all errors should be expressed in % AR.

Applications of Flowmeters

• Measurement of fluid, gas, or vapor flow

• Very large or very small flows

• Low or high temperature and pressure of fluids

• Gases or vapors present in pipes

• Fluids, gases, or vapors with complex settings or in large pipelines with flow

Choosing the Right Flow Meter

To choose the right flow meter, which is one of the flow measurement devices, accurate information about the type of flow, how data is transmitted (analog, digital, or shared), the minimum required frequency for data updates, characteristics and properties of the fluid flow process, and piping should be provided.