Mass Flow Meter

How does it work? 

In various industries and applications, the accurate measurement of fluid flow is crucial for process optimisation, quality control, and efficiency. Mass flow meters provide a reliable and precise solution for measuring the mass flow rate of gases and liquids. Unlike other flow measurement technologies that rely on pressure differentials or indirect measurements, mass flow meters directly measure the mass of the flowing fluid, making them highly accurate and unaffected by changes in temperature, pressure, or fluid composition.

Thermal Mass flow meter

What is a Mass Flow Meter?

Before diving into the details of mass flow meters, it is essential to grasp the difference between volumetric flow and mass flow. Volumetric flow refers to the measurement of the volume of fluid passing through a given point per unit of time, typically expressed in litres per minute (L/min) or cubic metres per hour (m³/h). Mass flow, on the other hand, measures the mass of the fluid per unit of time. Liquid mass flow is usually expressed in units such as kilograms per hour (kg/h) or grams per second (g/s). Gas mass flow, however, is mostly indicated in millilitres or litres per minute or hour, with additional “n” for normal temperature and pressure (NTP: 0 °C, 1 atm) or “s” for standard temperature and pressure (STP: 20 °C, 1 atm), for example ln/min or SLM.

Volumetric flow measurements can be affected by changes in temperature and pressure, as well as the composition of the fluid. Mass flow meters, however, provide accurate measurements by directly measuring the mass of the fluid, eliminating the need for additional corrections or compensations based on temperature or pressure variations

Learn more about volume flow vs mass flow measurement

Types of Mass Flow Meters

1.Thermal mass flow meters: these meters utilise the heat capacity of gases or liquids to measure their mass flow rate. Bronkhorst offers various thermal mass flow meters using different sensor techniques, including:

  • Bypass sensor (EL-FLOW Select and IN-FLOW series) for clean and dry gas applications.
  • Constant Temperature Anemometry (CTA) principle (MASS-STREAM, MASS-VIEW gas flow instruments series) for robust applications and virtually insensitive to moisture or particulates. The CTA principle is also used for liquid flow measurement (LIQUI-FLOW series).
  • MEMS chip-based sensors (FLEXI-FLOW and IQ+FLOW series), fast and smart instruments with small footprints and therefore ideal for applications in confined spaces.
2. Coriolis mass flow meters: these flow meters (mini CORI-FLOW series) operate on the Coriolis principle, which establishes a direct relationship between fluid mass flow rate and mass inertia. They are highly accurate, fast and fluid-independent, and can therefore be used for varying fluids and unknown compositions without requiring conversion.

Examples of Mass Flow Meters in Customer Applications

  • Mass flow meters for precise dosing of pharmaceutical agents: using a combination of Coriolis mass flow meters and WADose high-pressure pumps allows precise dosing of pharmaceutical agents. This powerful integration enables the administration of remarkably small quantities of pharmaceutical agents in liquid form, ensuring exceptional reproducibility. Read more…  
  • Hydrogen Storage Research: together with Wagner Mess- und Regeltechnik, Bronkhorst provided mass flow meters combined with a WADose HPLC pump and supported a German R&D institute in their quest to discover an innovative hydrogen storage solution. This pioneering approach involves utilising synthetic aromatic-based heat transfer oils commonly found in bakery systems and high-temperature applications. These oils serve as liquid organic hydrogen carriers (LOHCs), enabling efficient and safe hydrogen storage. Read more… 

Find your Mass Flow Meter

Thermal-based Mass Flow Meter

The benefits of a Mass Flow Meter

  • Provide direct measurement of mass flow, which is crucial in applications where mass is the primary parameter of interest.
  • Offer high accuracy and repeatability, ensuring precise measurement and consistent results.
  • Typically have a wide turndown ratio, allowing them to accurately measure a wide range of flow rates.
  • Provide real-time measurement and enable precise control of flow rates when used in combination with control valves or pumps. See our Mass Flow Controllers page.
  • Can be easily integrated with control systems, allowing for automation, data acquisition, and process optimisation.

Coriolis Mass Flow Meters
Coriolis Mass flow meter

To summarise, mass flow meters play a crucial role in accurately measuring fluid flow in industrial and scientific applications. With their ability to directly measure mass flow rates and their high accuracy, repeatability, and compatibility with different fluids, mass flow meters offer reliable and precise solutions for optimising processes and ensuring efficient operations. The examples of Bronkhorst products and customer applications highlight the practical use and benefits of mass flow meters in real-world scenarios.

Do you need help?

Let us know how we can help you to find the best solution for you. If you want to receive updates about trends in flow control and new product introductions, please sign up for our mailing list.

Contact us Discover our knowledge base