| 摘要 |
<p>Materials and structural components having irregular shapes may be tested by two ultrasonic testing heads which are movable in unison in the direction in which the cross-section of the material or component being tested changes. The synchroneously moving testing heads are spaced from each other in a direction extending across the moving direction. The testing heads are ultrasonic receivers connected with their outputs to a comparing device which provides an error signal when the amplitude ratio of the received signal changes. The amplitude ratio is formed between the amplitudes of the ultrasonic signals received by both testing heads. Preferably, the comparing device comprises an amplifier which amplifies the amplitude of the received second signal by an amplification factor which is proportional to a deviation of the amplitude of the received first signal from a reference value. The error signal is recorded, for example, by a coordinate plotter.</p> |
