APPARATUS FOR CONTACTLESS MEASUREMENTS OF LIQUID LEVEL IN TANKS

摘要

A device for contactless measurement of liquid level in a container by means of measurement of change of acoustic wave parameters, with acoustic wave sensors and sources and appropriate meters, consisting of a measurement tube of the diameter a few time lesser than the length located according to trajectory of free surface of liquid, the said tube is situated permanently in a container, the tube's bottom end is at the level of the minimum liquid level, and the top end is above the maximum liquid level, characterised in that it consists of a reference resonance pipe (17) of a determined length and diameter, located permanently next to the measurement pipe (12) in the container of liquid (13), and the bottom end of the reference resonance pipe (17) is located above the liquid level and is vaulted, whereas the top end of the reference resonance pipe (17) is equipped with a reference piezoelectric converter (15) and a reference microphone (14), which is connected to an input of a reference input voltage amplifier (8), whose output is connected to the first input of voltage amplitude detection circuit (5) equipped with an output connected to an input of an analogue-digital converter (2), whose input is connected to a microprocessor system (3) connected to an input of a programmed frequency divider (1), whose first input is connected to the second input of voltage amplitude detection circuit (5), and the second input is connected to an input of a frequency generator circuit (4) containing an output connected both to an input of output voltage amplifier (6) and to an input of measurement output voltage amplifier (7)...IMAGE