A METHOD OF DETERMINING THE MASS FLOW RATE

摘要

A method of determining the mass flow rate of a granular material through a channel 1 by means of electromagnetic microwaves where the attenuation and/or the phase-displacement is/are measured by means of a transmitter/receiver equipment 2, 3 at the channel 1. Most of the undesired signals in the measuring equipment are characterised by the phase versus the time varying in both positive and negative direction unlike a phase variation caused by grains in the measuring length, the latter phase variation only involving a phase-displacement in one direction. The undesired signal presents an average phase-displacement of zero and can therefore be deducted in order to obtain an improved measuring accuracy.