| 摘要 |
Two heads (2, 3) each comprise three sensors for measuring the propagation speed of ultrasonic waves, and thereby the degree of moisture and the temperature, in a test girder (1), in conjunction with a module (35) which has a microprocessor (31) and memories (32, 33, 34). The microprocessor calculates the measured propagation speed of the ultrasonic waves, this speed being normed with respect to a set temperature (e.g. 20 DEG C) and a set value (e.g. 15 %) of the degree of moisture. On this basis, the microprocessor searches for the class of standardized mechanical properties in which the material of the girder (1) falls. The microprocessor finds the class in which the value of said normed propagation speed falls in a memorized table of the maximum values of the propagation of these waves in the material in question. The apparatus makes it possible to determine the class automatically and non-destructively while eliminating the personal factor. |
