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: first ultrasonic wave is periodically excited with the aid of an acoustic radiator, the wave propagates through the walls and the liquid medium under inspection. The inlet point of the first longitudinal ultrasonic wave is selected below the level under inspection. The first longitudinal ultrasonic wave is picked up by the first acoustic receiver on the diametrically opposite side of the pipeline. The second ultrasonic wave, which is a longitudinal one reflected from the inner surface of the pipeline opposite wall, is picked up by the second acoustic receiver. The point of the second acoustic receiver corresponds to the level under inspection and is located on the same side as the acoustic radiator. The time zones of reception of the first and second ultrasonic waves are formed, and the peak value of ultrasonic waves are separated in them. Fixed information signals are formed at the preset threshold level of sensitivity, and the intermediate storage is controlled by them. If even one of the fixed sampled signals is available during the repetition period of the exciting pulses, an output signal is formed at the output of the intermediate storage, and the presence of liquid at the level under inspection is judged by it. EFFECT: enhanced reliability and accuracy of liquid measurement in industrial reservoirs and pipelines with a different thickness of walls and small diameters. 2 dwg
