DENSITY MEASURING INSTRUMENT AND DENSITY MEASURING METHOD

PROBLEM TO BE SOLVED: To provide a density measuring instrument capable of easily measuring the density of a measuring target of every kind. SOLUTION: In a case that the distance from the radiation surface of an acoustic lens 3 to the boundary surface of a couplant member 6 with air is larger than a focal distance, a sensor part 2 can not receive a reflected oblique incident sonic wave 32. An operational processing part 1 acquires a reference value from the reflected sonic wave received by the sensor part 2, that is, the reflected sonic wave formed by the reflection of a vertical incident sonic wave 30. Next, the operational processing part 1 measures acoustic impedance on the basis of the reflected sonic wave received by the sensor part 2 in the same way after the measurement target 9 is arranged. Further, the operational processing part 1 successively shortens the distance between the sensor part 2 and the measurmemt target 9 and measures the propagation speed of the sonic wave on the basis of a change in the intensity of the reflected sonic wave received by the sensor part 2. COPYRIGHT: (C)2007,JPO&INPIT