Patent ID: 7415880
Filing Date: 2008-08-26
Classification: G01B,G01N

Abstract:
1. A method for determining sound velocity Cb in a base material of a specimen to be tested, using an ultrasonic probe, the probe comprising: a transmitting transducer; a receiving transducer; and a precursor body; said precursor body: a) having a coupling surface by which the probe is couplable to the base material, b) carrying the receiving transducer and the transmitting transducer, and c) having a sound velocity Cv; said transmitting transducer and said receiving transducerbeing oriented to be inclined towards each other and each towards the coupling surface so that a main transmission direction of the transmitting transducer and a main receiving direction of the receiving transducer intersect below the coupling surface; said transmitting transducer and receiving transducerbeing spaced apart at a center to center distance K; said transmitting transducer and said receiving transducer being spaced at a center to center distance Dv from the coupling surface; said method comprising: generating an ultrasonic pulse by the transmitting transducer which is passed through the precursor body into the base material; the ultrasonic pulse producing a creeping wave in the base material, the creeping wave being a surface wave, at least a portion of the creeping wave reaching the receiving transducer via the precursor body; and measuring a shortest sound travel time Ttot of the ultrasonic pulse and the sound velocity Cb in the base material by a path between the transmitting transducer and the receiving transducer that supplies the shortest total travel time Ttot.