YJJ HAFUHM0020L4AXT Thermal Mass Flow Sensor 0-20SLPM for Medical Applications

Product Description:

YJJ HAFUHM0020L4AXT Thermal Mass Flow Sensor 0-20SLPM for Medical Applications

Features:

I. Core Parameters (25℃, 1 atm, air)

Model: HAFUHM0020L4AXT

Measurement medium: Dry, clean, oil-free air / non-corrosive gas

Range: 0–20 SLPM (standard liters per minute)

Accuracy: ±0.5% FS (full scale), ±0.5% reading

Repeatability: ±0.1% FS

Resolution: Up to 0.002 SLPM

Response time: ≤ 1 ms (fast dynamic)

Output interface: I2C (digital), slave address 0x49, 3.3V level

Power supply voltage: 3–10 VDC (typical 3.3V/5V)

Power consumption: Static approximately 25 mW, maximum ≤ 60 mW

Operating temperature: -20℃ to +70℃; medium compensation 0℃ to +50℃

Pressure resistance: Maximum 60 psi (≈4 bar)

Interface: 22 mm conical male connector (ISO 5356), quick-insert type

Package: 6-pin SIP connector, flame-retardant thermoplastic housing

Certification: RoHS compliant, medical-grade insulation and anti-interference

II. Model Interpretation (HAFUHM0020L4AXT)

HAF: Zephyr series

U: Universal type

HM: High precision + small range channel (different from HH/HT)

0020: Full scale 20 SLPM

L4: I2C output, 22mm quick-insert interface

AXT: Standard configuration, no special options

III. Working Principle

Using MEMS thermal microbridge:

Chip integrates insulation heating resistor + upstream and downstream temperature sensing resistors;

Airflow removes heat, the temperature difference upstream and downstream ∝ mass flow rate;

Built-in ASIC completes temperature compensation, linearization, digitization, and outputs I2C;

Directly measures mass flow rate, unaffected by temperature / pressure fluctuations.

IV. Main Applications (Low-flow high-precision scenarios)

Medical equipment:

Precise control of oxygen / air mixture ratio in ventilators / anesthesia machines

Low-flow monitoring for pulmonary function instruments, nebulizers (0–20 SLPM)

Industrial automation:

Precise gas ratioing (such as welding shielding gas, inert gas)

Leak detection equipment, gas analyzer low-flow calibration and stability

Environmental monitoring:

Low-flow closed-loop control for air sampling pumps, VOC analyzers

Research and laboratory:

Micro-flow measurement for gas pipelines, precision pneumatic equipment

Appliances / fresh air:

High-end air purifiers, medical-grade fresh air with low flow feedback

Specifications: