| 摘要 |
PURPOSE:To measure the thickness of a specific part of a sample by making an ultrasonic wave pulse incident on a sample from an ultrasonic wave transmitting and receiving means, and extracting and processing its reflected wave component by Fourier transformation. CONSTITUTION:When a transmission trigger signal which is outputted from a pulse control part 20 is inputted to a pulse wave transmission part 10, the transmission part 10 generates a single shot pulse and this pulse wave is converted by a transducer 11 into an acoustic signal, which is made incident on the sample 13 through an acoustic lens 12. Then the reflected wave from the sample 13 passes through the lens 12 again and is converted by the transducer 11 into an electric signal. This reflected signal contains components of a transmission omission, in-lens reflection, sample reflection, etc. A gate signal is used for gating to extract only a reflected wave component from the sample 13. This reflected component is converted into a digital signal through a sampling part 18 and an A/D conversion part 19 the signal is stored in the memory of a computer 21. |
