The wire's temperature increases with the wire’s electrical resistance, which limits electrical current flowing through the circuit. This is achieved by heating a wire with an electric current that is suspended in the engine’s air stream, not unlike a toaster wire. the vane has to be oriented with respect to gravityĪ hot wire mass airflow sensor determines the mass of air flowing into the engine’s air intake system.finding a suitable mounting location within a confined engine compartment is problematic.its moving electrical contacts can wear.it restricts airflow which limits engine output.The vane meter approach has some drawbacks: The vane measures air volume, not mass, however by measuring the air temperature and pressure to determine air density, a true mass airflow calculation can be achieved. The vane moves in proportion to the airflow, and a voltage is generated in proportion to the distance the vane moves. Also see MAP sensor.Ī vane, or paddle, projects into the engine’s intake air stream on a spring-loaded arm. The MAF sensor provides the open-loop predicted air flow information (the measured air flow) to the ECU, and the sensor provides closed-loop feedback in order to make minor corrections to the predicted air mass. When a MAF is used in conjunction with an oxygen sensor, the engine's air/fuel ratio can be controlled very accurately. Both sensor designs output a 0 - 5.0 volt signal that is proportional to the air mass flow rate, and both sensors have an intake air temperature (IAT) sensor incorporated into their housings. However, with an additional sensor or two, the engine's air mass flow rate can be accurately determined.īoth approaches are used almost exclusively on electronic fuel injection (EFI) engines. Neither design employs technology that measures air mass directly. These are the vane meter and the hot wire. There are two common types of mass airflow sensors in usage on gasoline engines. In automotive applications, air density varies with the ambient temperature and altitude, and this is an ideal application for a mass sensor. Air changes its density as it expands and contracts with temperature and pressure. ![]() The air mass information is necessary for the engine control unit (ECU) to calculate and deliver the correct fuel mass to the engine. MultiFlo™ technology allows one device to change gas types and ranges without removing the device from the system and improving actual process gas accuracy.A mass airflow sensor is used to determine the mass of air entering an electronically fuel-injected engine.Industry-best range of digital mass flow meters and other products to meet widest application needs.Key reasons why our mass flow sensors and controllers are the most widely used worldwide include: Precise process control is achieved through the combination of ultra-stable, highly accurate mass flow meter sensors, fast-responding flow control valves and powerful digital electronics. Mass flow meters and controllers:įor the industries that use mass flow fluid delivery - bioprocessing, semiconductors, thin film, chemicals and more - productivity, efficiency and profitability are all impacted by the reliability and repeatability of the process data generated by mass flow meters and the performance of fluid mass flow controllers. Our goal: to unlock new levels of thermal mass flow measurement precision, responsiveness, accuracy and repeatability. We are using new applications of digital technology to improve thermal mass flow sensors, mass flow meter designs and precision mass flow controller performance.Īs industry leaders, we continually launch new products and enhance our existing portfolio, including proven elastomer sealed, metal sealed, high temperature and Coriolis mass meters and controllers. To truly control any process, you must precisely measure what is happening - in the feedline, in the chamber, at every point - then use that information in real time to keep the process precisely on-target and productive.Īs the global leader in precision fluid measurement and control, mass flow meter manufacturer Brooks Instrument continues to drive innovation in thermal mass flow and Coriolis flow meter and control technology.
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