title: Automatic and simultaneous measurements of ultrasonic velocity and attenuation changes.
abstract: A method is described for measuring ultrasonic velocity and attenuation simultaneously by sampling echo pulses along with the repetition rate of velocity measurements. This is achieved by extending the pulse superposition method. This system enables us to measure the attenuation coefficient with a precision of 0.001 dB/cm, and the ultrasonic velocity with better precision than 1 part in 10(6). Velocity measurements can be made automatically up to five times the initial round trip time and can also track fast changes of 50 ms. Since the operation under the p=1 condition can be applied, the system can be used for the measurements of high-loss materials.
authors.affiliation: Department of Applied Physics, Faculty of Engineering, Nagoya University, Nagoya 464, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsuda
authors.forename: I
authors.initials: I
authors.lastname: Hatta