Gas mass flow measurement in pipe - has acoustic waves propagated upstream and downstream for measurement of velocity

摘要

The device has a first means (1) measuring the phase difference between a frequency propagating in and against the flow direction. There are second independent means (2) which measure the pressure in the pipe. and there are third means (3) which multiply the phase difference as the measure for V/T (flow velocity/absolute temperature) by pressure and by an instrument constant obtained by the device calibration. The apparatus uses only two transducers, (St1, St2) which are connected directly to the phase comparator (11). The device has linear characteristics.