Sonic Echo
The sonic echo method (impact test) is used for evaluating cracking of grouts, fracture of tendons and loss of element section. For this test method the specimen is impacted using a hammer or ball device, which generates elastic compression waves with relatively low frequency content. Equipment required for the impact echo test method includes an impact device, an accelerometer, velocity or displacement transducer for measuring the specimen response, and a data acquisition system. Components of the test are connected with standard coaxial cables and BNC connectors. Generally, an accelerometer is attached to the free end of the element and the impact is also applied to the free end.