METHOD OF DETERMINING LEVEL OF LIQUID IN HORIZONTAL METAL PIPE Russian patent published in 2011 - IPC G01F23/296 

FIELD: physics.

SUBSTANCE: method involves exciting sound waves on the surface of the pipe filled with liquid and then picking up the said waves with piezoelectric sensors mounted on the horizontal metal pipe. Sound waves are excited using a mechanical hammer, which consists of a metal housing, a clamp which holds a spring-loaded steel ball, and a trigger button as a trigger device. When the trigger button is pressed, the clamp opens, the spring is released and the steel ball strikes the surface of the metal pipe. A recording unit picks up and converts signals from piezoelectric sensors. Alternating signals from two piezoelectric sensors are rectified by amplitude detectors and are transmitted to sample-and-hold circuits on precision storage capacitors. The recording unit then connects identical load resistors to these charged storage capacitors. Since the converted signals from piezoelectric sensors have different values, the discharge time of their storage capacitors is different, and the difference between said discharge times Δt is proportional to the value of filling the pipe with liquid. This difference is stobed by a clock frequency, digitised, decoded and displayed on a liquid-crystal display and is expressed in percentages. The method can be implemented in pipes with cross-section of 50-1000 mm.

EFFECT: high accuracy and reliable measurement, mobility.

4 cl, 4 dwg