Air flow meter

Air Flow Meter

An air flow meter is a device used to measure the amount of air flowing through a system, typically through a tube or duct. It operates similarly to an anemometer, though it is specifically designed to measure the mass of air per unit time, rather than the volume. This distinction is important in applications where air density can change due to temperature or pressure variations.

Air flow meters are a specialized form of mass flow meters, calibrated for air as the working medium. The mass flow of air is commonly expressed in units such as kilograms per second (kg/s) or feet per minute (fpm). These units can be converted into volumetric measurements like cubic metres per second (m³/s) or cubic feet per minute (cfm), depending on the specific application and measurement needs.[1][2]

Applications In Automobiles Air flow meters, often referred to as mass air flow sensors (MAF sensors) in automotive applications, are used to determine the amount of air entering the engine. This information is critical for the engine control unit (ECU) to optimize the air-fuel ratio, ensuring efficient combustion and reducing emissions. These sensors are commonly found in modern fuel-injected engines.[3][4][5]

In Industrial Environments In industrial settings, air flow meters are used to monitor and regulate air in various forms—compressed, forced, or ambient. For instance:

In boiler systems, preheated air (commonly called combustion air) is mixed with fuel before ignition to maintain the correct fuel-to-air ratio.

In pharmaceutical manufacturing and coal pulverizing plants, air is used to control particle flow and maintain a dry, controlled atmosphere.

In mining and nuclear facilities, air flow meters help monitor ventilation systems to ensure a safe working environment by maintaining adequate airflow and preventing the buildup of hazardous gases.[6][7]

Related Technologies Anemometer – Measures wind speed and is often used in meteorology.

Mass flow sensor – Broader category of sensors including those that measure gases or liquids.

Thermal mass flow meter – A type of flow meter that uses temperature sensors to measure mass flow.

See Also Anemometer

Mass flow sensor

List of sensors

References Rowlett, Russ. How Many? A Dictionary of Units of Measurement. University of North Carolina at Chapel Hill. Archived from the original on 2 June 2018.

MEP Academy Instructor. (September 25, 2022). "Calculating CFM or Velocity Across a Coil or in Ductwork". MEPAcademy. Retrieved January 27, 2024.

Miata.net. Repair Broken Air Flow Meter, by Zach Warner, January 2, 2009.

Clark's Garage. AFM Shop Manual – Air Flow Meter Operation and Testing, 1998.

Auto Shop 101. AFM Sensor.

Spitzer, David W. (1990). Industrial Flow Measurement. ISBN 1-55617-243-5. 7. Think Aur AyouNi. (2024). “Air Flow Technology Explained” – A technical overview of air flow meter types, working principles, and industrial applications. Available at: https://thinkaurayouni.com/air-flow-technology-explained/. Accessed 20 May 2025.

Categories Engines

Engine fuel system technology