PORTABLE LIQUID LEVEL JUDGING APPARATUS, STANDARD MEMBER FOR CALIBRATION AND LIQUID LEVEL JUDGING METHOD WITHIN INTERNAL SPACE OF OBJECT

摘要

PROBLEM TO BE SOLVED: To facilitate the judgment from the outside of whether a liquid such as water is inside a pipe or the like or not. SOLUTION: In this portable liquid level judging apparatus, a probe 4 is applied on the external surface of an object to transmit an ultrasonic signal inside it. The ultrasonic signal propagating through the liquid inside to be reflected and received is displayed on a CRT7 with a delay in time from the transmitted signal. If no liquid exists, the ultrasonic signal propagating through the liquid is not received thereby enabling the judging of the liquid level depending on whether the liquid exists or not.