A narrow-band sing-around ultrasonic velocity measurement system

Abstract

Conventional sing-around systems for the measurement of ultrasonic velocity use short (broad-band) pulses. A novel sing-around system is reported in which the transmitted pulse has a narrow bandwidth (quasi-continuous wave), the triggering of the succeeding pulse being obtained from a preselected zero-crossing. The advantages of the technique stem from the avoidance of the problems involved in the conventional use of short (broad-band) pulses, which are particularly acute in highly dispersive media. Measurements on distilled water using the present system are reported, and agree well with those obtained using a conventional leading-edge detector system.