Thermal Mass Flow
FS-620Digital Thermal Gas Flow Meter
The FS-620 is a digital thermal gas flow meter for air and compatible gases. It is intended for compact OEM equipment that needs fast measurement, configurable ranges and Modbus connectivity.
Technical overview
Published configuration data
Values below describe catalog or typical configurations. The confirmed quotation and model code define the supplied specification.
- Range
- Multiple range options
- Pressure
- Configurations up to 1.1 MPa
- Protocol
- Modbus RTU
- Use
- OEM integration
Key characteristics
Why engineers consider FS-620
- Fast response
- Compact installation
- Digital communication
- Range and pressure options
Typical applications
Where it fits
- 01Analytical instruments
- 02Gas mixing systems
- 03Medical equipment
- 04Laboratory automation
Selection checklist
Confirm these conditions before ordering.
Sending this information helps CurioSens verify the measurement principle, materials, range and interface.
- 01Process medium and composition
- 02Minimum, normal and maximum measuring range
- 03Operating and sterilization temperature
- 04Operating pressure and pressure peaks
- 05Pipe or tube size and process connection
- 06Required output, power supply and control interface
Engineer-reviewed FAQ
Questions about FS-620
Application answers reviewed for compatibility, selection, installation and maintenance.
What is the difference between mass flow measurement and volumetric gas flow measurement?+
Gas volume changes substantially with fluctuations in process pressure and temperature, whereas mass remains constant. Thermal gas mass flow meters like the FS-600 and FS-620 utilize MEMS thermal sensing chips to directly measure molecular mass flow, outputting standardized mass or volumetric flow rates scaled to standard conditions such as 20°C and 101.325 kPa. This eliminates the added cost and potential error of installing secondary pressure and temperature sensors for compensation. Standard calibrations are performed using dry air, so multi-gas conversion factors or real-gas calibrations must be confirmed for the selected configuration. Provide your gas medium, flow range, pressure, temperature, viscosity, tube size, process connection, and required output for application verification.
comparisonWhat accuracy and turndown ratio does the FS-620 digital thermal gas flow meter achieve?+
The FS-620 thermal gas mass flow meter integrates a high-sensitivity MEMS sensing chip to measure dynamic gas flows with fast response times between 50 ms and 1000 ms. Featuring a 1:100 turndown ratio, standard full-scale models span from micro-flows of 0.001-0.1 L/min (0.00006-0.006 m3/h) to 3-300 L/min (0.18-18 m3/h). Standard body materials include anodized aluminum, 304, or 316 stainless steel with G1/2 or G1/4 female thread connections. Working pressure is rated at <= 1.1 MPa, with an optional 1.6 MPa rating. Gas calibration factors for specialty gases must be confirmed for the selected configuration. Contact our engineering team with your medium, flow range, pressure, temperature, viscosity, tube size, process connection, and required output.
selectionHow does the FC-620 gas mass flow controller differ from the FS-620 mass flow meter?+
The primary distinction lies in active flow regulation. The FS-620 acts purely as a measuring meter, outputting flow data via 4-20mA or RS485 Modbus. The FC-620 integrates a high-precision electromagnetic proportional valve and closed-loop control electronics, enabling automatic flow adjustment across a 1% to 100% FS control range with a stabilization time <= 1.5 seconds. The FC-620 operates across a maximum differential pressure of 0.6 MPa and working pressure up to 1.1 MPa. Both units feature a 1:100 turndown ratio and G1/4 thread connections. Specific valve differential pressure conditions must be confirmed for the selected configuration. Provide your gas medium, flow range, pressure, temperature, viscosity, tube size, process connection, and required output.
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