Honeywell Zephyr
TM
Digital Airflow Sensors
HAF Series–High Accuracy
±50 SCCM to ±750 SCCM
Datasheet
Honeywell Zephyr
TM
Digital Airflow Sensors
HAF Series - High Accuracy
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
available at ±50, ±100, ±200, ±400 or ±750 SCCM. Custom flow ranges are also available. The sensors are fully calibrated
and temperature compensated with an onboard Application Specific Integrated Circuit (ASIC).
The HAF Series is compensated over the temperature range of 0 °C to 50 °C [32 °F to 122 °F] and operates across a
temperature range of -20 °C to 70 °C [-4 °F to 158 °F]. The state-of-the-art ASIC-based compensation provides digital (I
2
C)
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.
What makes our sensors better?
Fast response time
Wide range of airflows
Customizable flow ranges and configurable package styles
Linear output
High stability
Low pressure drop
TIGHT TOTAL ERROR BAND • fAsT REspONsE TIME • WIDE RANGE Of AIRfLOWs
2
sensing.honeywell.com
Features
and Benefits
ToTAL Error BAnd (TEB) AS LoW AS 0.25%FSS*
Allows for precise airflow measurement, often ideal for demanding applications with
high accuracy requirements.
All Possible Errors
Offset
+
Full Scale Span
+
Linearity
=
Accuracy
+
Flow Hysteresis
Total
Error Band
+
Repeatability
=
+
Temperature Offset
+
Temperature Span
+
Thermal Hysteresis
Figure 1. Total Error Band vs. Accuracy
Other airflow sensor manufacturers only report on accuracy, while Honeywell reports Total Error Band.
FAST rESPonSE TIME*
Allows a customer’s application to respond quickly to airflow change, important in
critical medical (e.g., anesthesia) and industrial (e.g., fume hood) applications.
WIdE rAngE oF AIrFLoWS*
Zephyr measures mass flow at standard flow ranges of ±50, ±100 ±200, ±400
or ±750 SCCM, or custom flow ranges, increasing the options for integrating the
sensor into the application.
CuSToMIzABLE FLoW rAngES And ConFIgurABLE PACkAgE
STyLES*
Meet specific end-user needs.
FuLL CALIBrATIon And TEMPErATurE CoMPEnSATIon
Typically allow customer to remove additional components associated with signal
conditioning from the PCB, reducing PCB size as well as costs often associated
with those components (e.g., acquisition, inventory, assembly).
*Competitive Differentiator
sensing.honeywell.com
3
Features
and Benefits
LInEAr ouTPuT*
Provides more intuitive sensor signal than the raw output of basic airflow sensors,
which can help reduce production costs, design, and implementation time.
LoW PrESSurE droP*
Typically improves patient comfort in medical applications, and reduces noise and
system wear on other components such as motors and pumps.
HIgH 12-BIT rESoLuTIon
Increases ability to sense small airflow changes, allowing customers to more precisely
control their application.
LoW 3.3 VdC oPErATIng VoLTAgE oPTIon And LoW PoWEr
ConSuMPTIon
Allow for use in battery-driven and other portable applications.
ASIC-BASEd I
2
C dIgITAL ouTPuT CoMPATIBILITy
Eases integration to microprocessors or microcontrollers, reducing PCB complexity
and component count.
InSEnSITIVITy To ALTITudE
Eliminates customer-implemented altitude adjustments in the system, easing
integration and reducing production costs by not having to purchase additional
sensors for altitude adjustments.
SMALL SIzE
Occupies less space on PCB, allowing easier fit and potentially reducing production
costs; PCB size may also be reduced for easier fit into space-constrained
applications.
roHS-CoMPLIAnT MATErIALS
Meet Directive 2002/95/EC.
4
sensing.honeywell.com
*Competitive Differentiator
Potential Applications
MEdICAL
AnESTHESIA dELIVEry MACHInES
VEnTrICuLAr ASSIST dEVICES (HEArT PuMPS)
nEBuLIzErS
oxygEn ConCEnTrATorS
PATIEnT MonITorIng SySTEMS (rESPIrATory MonITorIng)
SLEEP APnEA MACHInES
SPIroMETErS
VEnTILATorS
LAPAroSCoPy
InduSTrIAL
AIr-To-FuEL rATIo
FuEL CELLS
gAS LEAk dETECTIon
VAV SySTEM on HVAC SySTEMS
gAS METErS
HVAC FILTErS
sensing.honeywell.com
5
