Compact bidirectional micro gas flow sensor Aosong AFS01 with digital I2C

Product Specification

Product Overview

The AFS01 is a high-precision, highly repeatable, and long-term stable micro gas flow sensor. Utilizing a self-developed thermal flow chip and a high-performance 24-bit AD acquisition CMOS microprocessor, it offers excellent integration and cost-effectiveness. The sensor operates on a 5V supply voltage and communicates via I2C digital interface. Its compact size makes it suitable for various gas flow measurement applications. The AFS01 undergoes rigorous factory calibration, allowing users to obtain detected flow rates directly through read commands, thereby reducing usage costs and secondary development complexity. It is designed for bidirectional measurement and is factory calibrated with air under standard conditions (25, 1 atm).

Application Scenarios:

• Gas flow monitoring in medical physiotherapy equipment
• Gas ratio monitoring for special effect technologies (e.g., smoke)
• Gas ratio monitoring for fragrances and spices
• Industrial gas flow monitoring
• Precision dripping volume monitoring for industrial filling

Product Attributes

• Brand: ASAIR (Guangzhou Aosong Electronics Co., Ltd.)
• Model: AFS01
• Communication Interface: I2C
• Measurement Principle: Thermal transfer
• Measurement Direction: Bidirectional
• Calibration: Factory calibrated (Standard conditions)
• Standard Calibration Gas: Air (Standard conditions)
• Certifications: AEC-Q-100-002 (4kV HBM), AEC-Q-100-003 (200V MM)

Technical Specifications

Communication Protocol

The AFS01 utilizes the standard I2C communication protocol with two data lines: SDA (Serial Data Bus) and SCL (Serial Clock Bus). Each device on the bus has a unique address. The sensor acts as a slave device with an I2C address of 0x40.

CRC Checksum

The sensor uses CRC8 checksum algorithm for data verification. The initial value is 0x00, and the polynomial is 0x31 (x⁸ + x⁵ + x⁴ + 1).

Data Acquisition

Data is acquired by the sensor every 500ms. Users can retrieve flow data using the specified command. The data is returned in sccm.

Sensor Commands

• Flow Acquisition Command: Host sends 0x10 (Byte 1), 0x00 (Byte 2). Sensor returns 8-bit high flow, 8-bit low flow, and CRC.
• Read Sensor ID Command: Host sends 0x31 (Byte 1), 0xAE (Byte 2). Sensor returns 16-bit high ID, CRC, 16-bit low ID, CRC.

Important Notes

• ESD Protection: The sensor complies with AEC-Q-100-002 (4kV HBM) and AEC-Q-100-003 (200V MM). Handle with anti-static precautions (e.g., wrist straps, insulated gloves).
• I2C Wiring: Keep I2C connection lines as short as possible, recommended maximum length of 1m. For lines over 30cm, widen traces on the PCB.
• Installation: Avoid excessive bends (>45) in inlet/outlet tubes. Ensure L1 and L2 lengths are >10cm for stable measurements. Install in a dry, shaded environment.
• Applications: Do not use in safety protection or emergency stop devices where failure could cause personal injury, unless specifically authorized.

Quality Assurance

Guangzhou Aosong Electronics Co., Ltd. provides a 12-month warranty for the AFS01 gas micro flow sensor from the date of product inspection, based on the technical specifications in the published datasheet. Free repair or replacement is offered for confirmed defects within the warranty period.