Siargo Mass Flow Sensors

fs35001 manifold mass flow sensor

FS35001 series of gas mass flow sensors for general-purpose gas flow monitor and control applications with a full-scale mass flow rate from 0.2 to 20 SLPM, and both analog and digital outputs.

FS35001 mass flow sensors are designed in the manifold configuration for mechanical connections. Optionally it can also be offered with a manifold body with 4mm one-touch flexible piping. It can be applied to medical equipment and instrumentation applications. The series covers a wide dynamic flow range with a working pressure rating of up to 1.0 MPa (10 bar or 150 PSI), and a compensated temperature ranging from -5 to 50°C.

The sensing elements are manufactured with Siargo’s proprietary MEMS (micro-electro-mechanical systems) thermal mass flow sensing technologies (Thermal-D®) that measures the calorimetry and diffusivity of the flow medium. The sensor surface is passivated with silicon nitride ceramic materials together with 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 to sense 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.


  • ±1% or 0.2%FS at ±20°C (can be customized to 25°C)
  • Response time: programmable from 2 msec
  • Pressure rating: 10 var
  • Bi-directional sensing: symmetrical, same error band
  • Power is 8-24 VDC
  • Interface: 0-5VDC, I2C, RS485, RS232, 4-20 mA
  • Wire sealed to medium gives better reliability
  • Pressure balancer in membrane creates less pressure effects at pressure change or high pressure ratings
  • Reference temperature is away from the heater creating better temperature accuracy