Thermal mass flow meters use changes in temperature and heat transfer to measure the mass flow rate. In these meters, a heating element is used to heat the fluid. As the fluid flows, it carries away the heat, causing a temperature drop that is proportional to the mass flow rate. By measuring this temperature drop, the flow rate can be calculated.

Changes in Fluid Properties

Some mass flow meters measure changes in fluid properties, such as pressure, density, or temperature, to infer the mass flow rate. These meters are often used for gases and can provide accurate measurements even under varying conditions.

Types of Mass Flow Meters

Mass flow meters come in various types, each with its own advantages and applications. The three main types are:

Coriolis Mass Flow Meters

As mentioned, Coriolis mass flow meters are the most common type. They offer high precision and accuracy, making them ideal for applications where precise mass flow measurements are essential. They can measure both liquids and gases and are suitable for both single and multi-phase flows.

Thermal Mass Flow Meters

Thermal mass flow meters are simple and cost-effective. They are often used for gases and can provide accurate measurements even under varying conditions. These meters are commonly used in semiconductor manufacturing, chemical processing, and other industries where gas flow needs to be closely controlled.

Volumetric Mass Flow Meters

Volumetric mass flow meters measure the volume of fluid passing through a pipe and then use this volume to calculate the mass flow rate. While they are less accurate than pure mass flow meters, they are often used where mass flow is not critical, and volumetric flow rate is sufficient.

Applications of Mass Flow Meters

Mass flow meters are widely used in various industries due to their precision and reliability. Common applications include:

Chemical and Petrochemical Industries

In these industries, precise control of reactants and products is crucial. Mass flow meters ensure that the correct amounts of fluids are processed, leading to improved efficiency and product quality.

Semiconductor Manufacturing

Mass flow meters are essential in semiconductor manufacturing, where precise control of gases and chemicals throughout the manufacturing process is critical for achieving high yield and product quality.

Food and Beverage Industry

In this industry, mass flow meters are used to accurately measure the flow of liquids, ensuring consistent product quality and meeting strict regulatory requirements.

The Myths and Truths About Mass Flow Meters

There is a common misconception that “the” mass flow meter is actually a bucket or other container on a scale balance with a timing device. This is not true. While a balance could indirectly measure mass flow, mass flow meters are specialized devices designed to measure mass flow directly and accurately in real-time.

Other devices that are called mass flow meters may measure a quantity that is proportional to mass flow and may vary with the actual flow. These meters provide useful information, but they do not directly measure mass flow in the same way that a Coriolis meter or a thermal meter does.

Understanding the principles, types, and applications of mass flow meters can help you to select the right meter for your specific needs, whether in a scientific laboratory, a manufacturing plant, or any other environment where accurate flow measurement is critical.

Keywords: mass flow meter, Coriolis effect, thermal dispersion