Non Contact Solid Flow Measurement

Doppler Non Contact Solid Flow Switch

The Doppler Flow Switch emits a low power microwave signal toward the material being monitored. Part of this signal is reflected off the material back to the antenna of the Doppler Flow Switch. This reflected signal combines with the emitted signal to produce a beat

frequency, which is the difference in frequency between the two signals. If the material being monitored is not moving, the reflected signal will be the same frequency as the emitted signal and there will be no beat frequency produced. However, if the material is moving, the reflected signal will be shifted in frequency and a difference or beat frequency will be produced. This shift in frequency is called the Doppler effect. The presence or absence of this beat frequency is sensed by the Doppler Flow Switch to detect a flow or no flow condition.

Microwave Non Contact Solid Flow Meter

The measurement principle of the Microwave Solid Flow Meter is based on the physical Doppler-Effect, whereas the sensor generates a uniform field in the microwave frequency range inside the pipeline. These microwaves are being reflected by particles passing through the pipe. Calculation of frequency and amplitude changes allows an accurate determination of the solid’s mass flow rate. Nonmoving particles like dust accumulation are excluded from calculations.