Difference Between Mass Flow and Volumetric Flow

Measurement of fluid flow in accurate matters in various engineering and industrial applications, which ensures optimal performance and efficiency. There are obvious advantages from measuring mass flow than volumetric flow, especially for compressed air and technical gases like argon, co2 and nitrogen. Read the article and perceive professional insight in both measurement.

What is mass flow?

Mass flow refers to the measure of a mass passing per unit time. Mass represents the total number of molecules moving through specific vessels, not affected by changes of temperature and pressure. Different with volume, the mass of a gas stays constant in despite of fluctuations in environmental conditions. Mass flow rate is described in units like kilograms per hour (kg/hr) or pounds per minute (lb/min); gases are described in standard cubic meters per hour (Nm³/hr) or standard cubic feet per minute (SCFM).

What is Volumetric Flow?

Volumetric flow refers to actual flow, measuring a volume moving per unit time. m3/hr, m3/min, CFM or ACFM are common units for volumetric flow, which are applied to describe how big it is in a three-dimensional space. Volume of gases are directly proportional to temperature and pressure. The volume of a gas expands with increasing temperature and pressure; on the contrary, it shrinks with decreasing temperature and pressure. In other words, temperature and pressure should be taken into consider when measuring volumetric flow.

Mass flow rate vs volumetric flow rate

Detailed knowledge of mass flow rate and volumetric flow rate is beneficial to choose the appropriate measurement technique. Mass flow rate is extremely accurate and reliable in processes, in which density of the fluid may change with that of temperature and pressure. This technology is popular in industries attaching much importance to precision control over fluid properties, such as pharmaceuticals and petrochemicals.

On the contrary, volumetric flow measurement is powerful enough in industries where accuracy is less important. For example, the method is reliable enough in monitoring and controlling flow in agricultural irrigation system and water distribution networks, not to mention complex compensations needed in processing. Volumetric is a simpler and more cost-effective option in specific industries. Inaccuracies may occur in case the environmental conditions are not managed properly.

Benefits of Mass Flow Measurement

The primary benefit of utilizing mass flow measurement rest on its accuracy and reliability, reducing dependency on temperature and pressure corrections. The direct correlation between mass flow and the properties of the fluid allows for real-time monitoring without the complexities of compensatory calculations.

Choose mass flow measurement for more accurate processing control. Informed decisions could be made by operators with precision flow date at their disposal to reduce waste and enhance product quality. Constant monitoring of mass flow rates allows operators to adjust according to changing conditions, leaving your operations to stay efficient and effective.

When to use a volumetric flow meter or a mass flow meter?

Volumetric flow meters are recommended for applications attaching less importance to high accuracy. Nevertheless, a volume meter needs additional compensation from additional temperature and pressure. Whereas additional information on temperature and pressure could not pose a threat on a higher accuracy and repeatability. Therefore, mass flow meters are more reliable and accurate when compared with volumetric flow meters.

When to use a volumetric flow meter or a mass flow meter?

Advantages of mass flow meters force people who are accustomed to volumetric flow meters to make some changes in special industry processing. Fortunately, it’s easy to provide flows in volume with a mass flow meter, reaching the objective by adding volume (a.k.a the pipe diameter) to the flow meter.

How to convert mass flow to volumetric flow?

Perhaps it’s necessary sometimes to convert mass flow to volumetric flow. The conversion is reached after using a straightforward formula, applying the relevant density values into the following equation.

Volumetric Flow Rate=Mass Flow Rate​/Density

The density relates the mass flow rate to the volumetric flow rate. And density is inversely proportional to temperature and pressure. Namely, high temperatures cause low densities and high pressures cause low densities, too. The volumetric flow rate is obtained by dividing the mass flow rate by the fluid density. A volumetric flow rate varies with temperature and pressure, while a mass flow rate remains constant when temperature or pressure changes.

Integrated flow measurement systems featuring automation solutions enhance efficiency and quality of final products significantly. Moreover, fine-tuning in flow rates and real-time analytics make contributions to optimal operation without any process disruptions. The proactive method takes effects on both streamlined operations and ongoing improvements.

In summary, understanding the nuances of mass flow and volumetric flow measurements is vital for optimizing performance in various applications. By leveraging the right measurement techniques and embracing the strengths of each approach, professionals can enhance their operations and achieve greater accuracy in their fluid management processes.