Possible applications

• Damper control for heating, ventilation, and air conditioning systems
• Gas analyzers
• Process control
• Medical devices and ventilators
• Oxygen concentrators
• Leak detectors
• Gas chromatography

Functionality

In simple terms, an air flow sensor is a device with two pressure ports through which gas flows from one port to the other (see Figure 1). Inside the sensor is a sensitive measuring element with a heated surface.

When air or gas flows across the sensing element, heat is transferred in the upstream direction, as illustrated in Figure 2. This creates a temperature difference that is proportional to the mass flow of the medium. The temperature difference is measured by an electronic circuit and converted into a corresponding output signal.