| 摘要 |
<p>The ultrasonic flaw detector for finned tubes uses the pulse-method of operation. The test equipment differentiates between normal echoes from inner and outer walls of the tube and those from the region of the fin or external rib. The tube under investigation (1) is inserted into the test cylinder (4) and is held in position by clamping blocks (10). The cylinder is sealed and filled with water. Two ultrasonic transducers for transmission and detection are mounted at 180 deg. apart on the cylinder (5a, 5b) and are energised from the sender/receiver (15) via inductive conductor rings (13)(14). A blocking circuit (16)(17) suppresses the detector signals during the period when the detectors are passing the finned part of the tube.</p> |
