Honeywell ZephyrTM Digital Airflow Sensors
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Honeywell ZephyrTM Digital Airflow Sensors HAF Series—High Accuracy: 10 SLPM, 15 SLPM, 20 SLPM, 50 SLPM, 100 SLPM, 200 SLPM, 300 SLPM DESCRIPTION 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 10 SLPM, 15 SLPM, 20 SLPM, 50 SLPM, 100 SLPM, 200 SLPM and 300 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 >10 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. • Precise measurement: The industry’s smallest Total Error Band, fast response time, and high accuracy provide precise measurement and high performance in the customer’s application. • Saves time: Configurable and customizable with a choice of port styles simplifies design and reduces production time. • Cost-effective: Reduces printed circuit board (PCB) size and overall design and production costs. FEATURES • Fast response time (1 ms) allows the customer’s application to respond quickly to a change in airflow, important in critical medical (e.g., anesthesia) and industrial (e.g., fume hood) applications. • High stability reduces errors due to thermal effects and null shift, providing accurate readings over time and often eliminating the need for system calibration after PCB mount and periodically over time. • High sensitivity at very low flows provides a fast response time at the onset or cessation of flow. • High 12-bit resolution increases the ability to sense small airflow changes, allowing customers to more precisely control their application. • Wide airflow range: The industry’s broadest airflow range measures mass flow with standard flow ranges of 0 to10, 0 to 15, 0 to 20, 0 to 50, 0 to 100, 0 to 200 and 0 SLPM to 300 SLPM, or custom flow ranges, increasing the options to integrate the sensor into the application. • Choice of port styles: Manifold mount, 22 mm OD tapered male fitting, and G 3/8 female threaded fitting provide flexibility to choose the pneumatic connection that is best for the customer’s application. • Linear output provides a more intuitive sensor signal than the raw output of basic airflow sensors, which can help reduce production costs, design, and implementation time. • Wide supply voltage range (3 Vdc to 10 Vdc) provides a flexible regulated power circuit which allows the designer the flexibility to choose the supply voltage that works best in the system. • ASIC-based I2C digital output simplifies integration to microprocessors or microcontrollers, reducing PCB complexity and component count. • RoHS-compliant materials Meet Directive 2002/95/EC. POTENTIAL APPLICATIONS • Medical: Anesthesia delivery machines, ventilators, ventricular assist devices (heart pumps), spirometers, laparoscopy • Industrial: Analytic instrumentation (spectrometry, chromatrography), air-to-fuel ratio, fuel cells, fume hoods, gas leak detection, process control gas monitoring, vacuum pump monitoring PORTFOLIO The Honeywell Zephyr Digital Airflow Sensors join an extensive line of airflow sensors for potential use in me

Honeywell ZephyrTM Digital Airflow Sensors Honeywell ZephyrTM Digital Airflow Sensors Figure 1. Total Error Band vs. Accuracy Full Scale Span Pressure Non-Linearity Accuracy BFSL Pressure Hysteresis Pressure Non-Repeatability Thermal Effect on Offset Full scale (FS) flow Total Error Band Operating temperature range Supply current Power: 3 Vdc 10 Vdc Calibrated temperature range1 Supply voltage Other airflow sensor manufacturers only report on accuracy, while Honeywell reports Total Error Band. Calilbrated flow range Thermal Effect on Span Thermal Hysteresis HIGH ACCURACY Honeywell specifies...

Honeywell ZephyrTM Digital Airflow Sensors Honeywell ZephyrTM Digital Airflow Sensors HAF Series—High Accuracy: 10, 15, 20, 50, 100, 200, 300 SLPM Table 3. Environmental Specifications Characteristic Figure 2. Nomenclature and Order Guide1 ESD IEC6100-4-2 air discharge up to 8 kV, or direct contact discharge up to 4 kV Level 3 from 80 MHz to 1000 MHz per IEC61000-4-3 1 m shielded cable with 3 cm exposed leads at connector 1 m shielded cable with 3 cm exposed leads at connector and 280 Ohm at MHz ferrite bead Product Series For example, HAFUHM0020L4AXT defines a Honeywell ZephyrTM Airflow...

Honeywell ZephyrTM Digital Airflow Sensors Honeywell ZephyrTM Digital Airflow Sensors Figure 6. Flow vs Pressure Drop: 10, 15, 20, 50, 100, 200, 300 SLPM Flow (SLPM) Digital Output (Counts) Full Scale Flow (%) Total Error Band: 0%FS to 12.5%FS = 0.5% 12.5%FS to 100%FS = 4.0% Figure 5. Accuracy and Total Error Band Typical Pressure Drop Table 6. Ideal Transfer Function Digital Output Code Flow Applied Equation 16384 * [0.1 + 0.8 * (Flow Applied/Full Scale Flow)] Full Scale Flow * [(Digital Output Code/16384) - 0.1]/0.8 Digital Interface For additional details on the use of Zephyr with...