Microwave resonating sensors for real time weight monitoring of powdered, granular and liquid samples

The use of microwave sensors has been demonstrated to be very appealing for real time applications in industrial processes, thanks to their fast, low cost real time measurement capabilities. The limit on the application of this measurement technique in production lines can be the errors and uncertainties due to both tolerances of mechanical parts and repeatability associated to the undesired positioning shift especially on massive and fast production lines. This paper presents both simulation and measurement results obtained to validate the use of an X-band microwave resonant sensor for the real time measurement of mass of granular and fluid samples in industrial processes. The proposed approach and the results obtained demonstrate the robustness of the sensor, with an expected accuracy on weight measurement of « 50 µg.