Zephyr™ Digital Airflow Sensors (HAF Series)

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Honeywell Zephyr™ HAF Series sensors provide a digital interface for reading airflow over specified full-scale flow and compensated temperature ranges. The thermally isolated heater and temperature sensing elements help these sensors provide a fast response to air or gas flow.

Zephyr sensors are designed to measure mass flow of air and other non-corrosive gases. Standard flow ranges are 20 SLPM or 200 SLPM, with custom flow ranges available. The sensors are fully calibrated and temperature compensated with an onboard Application Specific Integrated Circuit (ASIC).

The HAF Series >20 SLPM is compensated over the calibrated temperature range of 0 °C to 50 °C [32 °F to 122 °F]. The state-of-the-art ASIC-based compensation provides digital (I2C) outputs with a response time of 1 ms.

These sensors operate on the heat transfer principle to measure mass airflow. They consist of a microbridge Microelectronic and Microelectromechanical System (MEMS) with temperature-sensitive resistors deposited with thin films of platinum and silicon nitride. The MEMS sensing die is located in a precise and carefully designed airflow channel to provide repeatable response to flow.

Zephyr sensors provide the customer with enhanced reliability, high accuracy, repeatable measurements and the ability to customize sensor options to meet many specific application needs. The combination of rugged housings with a stable substrate makes these products extremely robust. They are designed and manufactured according to ISO 9001 standards.


  • Total Error Band (TEB) is ±0.5 %FS or ±4% reading, whichever is greater
  • High accuracy (±3.5% reading)
  • Fast response time
  • Wide range of airflows
  • Full calibration and temperature compensation
  • High sensitivity at very low flows
  • Linear output provides more intuitive sensor signal than the raw output of basic airflow sensors
  • Customizable flow ranges and configurable package styles
  • High stability
  • Low pressure drop
  • High 12-bit resolution
  • Flexible regulated powers from 3 Vdc to 10 Vdc
  • ASIC-based I2C digital output
  • RoHS-compliant
  • Choice of port styles


  • Medical
    • Anesthesia delivery machines
    • Ventricular assist devices (heart pumps)
    • Patient monitoring systems (respiratory monitoring)
    • Spirometers
    • Ventilators
    • Laparoscopy
  • Industrial
    • Air-to-fuel ratio
    • Analytical instrumentation (spectrometry, chromatography)
    • Fuel cells
    • Gas leak detection
    • Gas meters
    • Fume hoods


Airflow Sensor Line Guide (PDF)
Datasheet (PDF)