OIL LEVEL DETECTION DEVICE WITHIN CLOSED CONTAINER ACCORDING TO ULTRASONIC WAVE

摘要

PURPOSE: To enable an oil level position within a tank to be detected accurately by fixing a parallel ultrasonic reflection plate for a side wall within a sealed type metal tank and then providing an ultrasonic probe which can move up and down on an outer-wall surface of the tank so that the probe opposes the wall. ;CONSTITUTION: A reflection wave is scanned by moving an ultrasonic probe 11 in upper and lower directions. An ultrasonic flaw-detection machine 12 detects arrival time and strength of the reflection wave according to the reflection wave. A high detection sensitivity can be obtained since the probe 11 detects a reflection wave with a large strength from an ultrasonic reflection plate 21. Also, arrival time and strength of the reflection wave change in steps corresponding to a difference in propagation characteristics of ultrasonic wave at liquid-phase and gaseous phase parts of fluorocarbon with a liquid face 7 as a boundary in scanning process. By detecting this step-shaped change point, a position of the liquid face 7 can be known. By marking a detection liquid-face position on an outer-wall surface of the tank at the time of initial measurement, presence or absence of failure of closing performance can be judged easily according to deviation of the liquid-face position which is detected at the time of periodical inspection.;COPYRIGHT: (C)1993,JPO&Japio