Application of acoustic method for determination of coordinates of leakage in cavities bounded by large surfaces

Abstract

It is shown that the two-dimensional problem has to be solved while determining the co-ordinates of leakage in cavities bounded by the large surfaces. When the co-ordinates of the leakage are determined by an acoustic correlation measuring method the difference of times of propagation of acoustical noises from the leakage place to the electroacoustical transducers is measured. Since the difference of distances from the leakage place to electroacoustical transducers is constant, the difference of times of propagation of acoustical noises from the leakage to the electroacoustical transducers is constant too. So any point of leakage corresponds the hyperbola the focus points of which coincide the places of transducer location. At that case, while using only two measuring transducers, the ambiguity of measuring results corresponding the leakage co-ordinates is obtained. With the purpose to avoid the ambiguity of measuring results it was proposed to introduce one more electroacoustical transducer. At such case, depending on the co-ordinates of the leakage and the location of electroacoustical transducers, the system of equation, which describes the co-ordinates of the leakage, may have 2, 3 or 4 real solutions. With the purpose to discover, which of the determined co-ordinates is true, it was proposed to supply to the measuring system, the additional electroacoustical transducer. When using three independent couples of electroacoustical transducers three hyperbolas are obtained and they have only one common point of intersection. This point is the place of leakage on the controllable plane. In this way it is possible to determine the position of leakage on the plane unambiguously. The proposed method and algorithms may be applied while creating ultrasonic systems for determination of co-ordinates of leakage in cavities bounded by the large surfaces.