FIELD: procedure of inspection of presence of liquid in process reservoirs and pipelines with a cylindrical or like shape, applicable in metallurgical, chemical, petroleum refining, water treatment and other branches of industry. SUBSTANCE: ultrasonic wave is periodically excited with the aid of an inclined radiator in the inlet point that is located on the pipeline outer surface. The ultrasonic wave propagates in the wall from the inlet point to the reception point. The reception point is selected on the intersection of the helical paths which are formed by two symmetrical side ultrasonic beams of the radiator. The divergence angle of the main lobe of the radiator radiation pattern is selected at a level of 0.7. The ultrasonic reception point is removed from the inlet point at a preset distance along the pipeline equal to multiple odd number of half-periods of the helical path of each ultrasonic beam. Side ultrasonic beams are summed up in the reception point, and the wave amplitude is formed according to them. The voltage that corresponds to the peak value in each period of excitation of the ultrasonic wave is memorized and compared with the reference voltage. The presence or overshoot of liquid in the pipeline is judged by the difference of voltages. EFFECT: enhanced reliability and accuracy of determination of the presence or overshoot of liquid in pipelines. 3 dwg
