Siargo Mass Flow Sensors

FS1100 Medical Mass Flow Sensors

The FS1100 sensors measure the mass flow rates with a full scale up to 250 SLPM with a dynamic range of 100:1, and a temperature measurement of -20°C to 85°C. It has a maximum pressure rating of 2 bar (30 psi). Flow range selections include reverse to forward flow rates.

The sensor can be sterilized via a medical cleansing agent compatible with the wetted materials of polycarbonate, silicon nitride, and medical-grade epoxy LOCTITE 84-3J. Alcohol is not recommended for use as it may react with polycarbonate. A recommended alternative is to use standard dry EtO sterilization.

The sensing elements are manufactured with Siargo’s proprietary MEMS thermal mass flow sensing technology (Thermal‐D®) that measures the calorimetry and diffusivity of the flow medium. The sensor surface is passivated with silicon nitride ceramic materials and water/oilproof nano‐coating for performance and reliability. Compared to the conventional calorimetric flow sensing technology, this unique sensing approach offers better linearity, removes gas sensitivity for gases with similar thermal diffusivities, and improves temperature performance. It can also auto‐recognize pre‐programmed gases with significant differences in thermal diffusivity. It is the first in the industry that senses the mass flow with multiple gases without a manual gas conversion factor. As such, it ensures high precision for gas measurements with air calibration.

Thermal-D ® is a trademark of Siargo’s thermal sensing technology.


  • Various mass flow ranges from -250 to +250 SLPM (ability to measure in 2 directions)
  • Pressure rating up to 2 bar
  • Output choices of linear analog: 0.5 to 2.5 VDC, Digital I2C
  • Accuracy of ±2% + 0.5 FS


  • Medical ventilators and other medical equipment