LPG level indication in pipe - uses pulsator for pipe wall vibration probe, probe signal processor and digital indicator

摘要

The appts. involves a pulse unit which causes the vessel's wall to oscillate, and a transmitter which probes the varying oscillatory behaviour dependent upon the degree to which the vessel is filled. In the gas vessel there is an excess pressure which maintains the gas in the fluid phase, and where gas is vacated via a valve, there is renewed gasification to the excess pressure level, with subsequent lowering of the fluid level. The vibrations produced by the pulse unit are damped in frequency and amplitude by the fluid and the excess pressure. The damped wall oscillations are probed by a piezo-electrical detector, and evaluated in a connected processor, the results being presented on a digital type indicator. (Provisional Basic advised week 84/02).