Next generation compact flow sensor, 2.3% m.v. accuracy
The SFM3505-300 is part of our next-generation compact digital flow meter family, succeeding the proven SFM3119 and SFM3100. Featuring a completely re-engineered architecture, it delivers best-in-class performance with ultra-low noise and high accuracy across an extended flow range from –150 to +300 slm. The sensor is offered in two performance tiers, SFM3505-300 with standard (2.3% m.v.) and SFM3505-300-X with high (1.5% m.v.) accuracy.
Built on Sensirion’s latest 5th-generation CMOSens® Technology, the SFM3505 integrates the sensor element and advanced signal processing on a single microchip. This enables fast, stable, and fully calibrated digital output via a standard I²C interface, ensuring long-term reliability and robust operation over the sensor’s lifetime.
It is calibrated for air and oxygen and incorporates on-chip temperature compensation, ensuring precise measurements under varying conditions. Its optimized flow channel design enables minimal pressure drop across the full dynamic range, making it ideal for inspiratory flow measurements in applications such as mechanical ventilation, anesthesia, and gas mixing systems.
| Gas flow | |||
|---|---|---|---|
| Full scale flow rate -150 - 300 | -150 - 300 | slm | |
| Typical accuracy 2.3% m.v. | 2.3% m.v. | ||
| Calibration Air and O₂ | Air and O₂ | ||
| Sensor output Flow | Flow | ||
| Maximum operating pressure 1.65 | 1.65 | bar | |
| Fluidic connector ports O-Ring | O-Ring |
| Generic | |||
|---|---|---|---|
| Supply voltage 3.2 - 3.4 | 3.2 - 3.4 | V | |
| Max. supply current 10 | 10 | mA | |
| Interfaces I²C | I²C | ||
| Size (LxWxH) 57.5 x 27.5 x 29.4 | 57.5 x 27.5 x 29.4 | mm |
Buy the following products to evaluate this sensor
| Name | Description | Series | Category |
|---|---|---|---|
SEK-SFM3505 | Gas flow sensor evaluation kit SFM3505 | SFM3xxx | Gas flow sensors |

Sensirion's sensor solutions are used in a wide range of applications and markets. Our reliable environmental and flow sensors improve energy efficiency, increase health and ensure safety and comfort.