- The sensor may be incorrectly installed — for example, not centered or installed at the wrong depth.
- The wrong gas type, flow units, or reference conditions may be selected in the settings.
- The inner pipe diameter might be entered incorrectly in the software.
- The sensor technology may not be suitable for the current application (e.g., thermal mass sensors in very humid environments).
- There may not be enough straight pipe before or after the sensor, causing turbulent flow.
- Verify the sensor is properly centered in the pipe and installed at the recommended depth and orientation.
- Check the gas type, measurement units, and reference pressure/temperature conditions in the S4C-FS software.
- Enter the correct inner pipe diameter to ensure proper flow calculation.
- Make sure the sensor technology is appropriate for the gas conditions (e.g., avoid thermal mass sensors where liquid water may be present).
- Install the sensor with adequate straight pipe lengths before and after, as specified in the manual.










