Acoustic property measurement of ultrasonic delay line.

Abstract

The acoustic properties of F05 ultrasonic delay-line glass produced by the Shanghai Xin-Fu Glass Factory are measured with an instrument built by this institute. The instrument can automatically and continuously measure a small variation of ultrasonic velocity by a pulse superposition (PS) method with a solution of 2×10−7; precisely measure absolute ultrasonic velocity by a pulse echo overlap (PEO) method with a precision of 1×10−4; and automatically and continuously measure ultrasonic attenuation by a gated echoes comparison (GEC) method with a resolution of 0.1 dB. Three parts in one instrument not only can possess the advantage of convenience, but also can overcome the shortage of determining the absolute value by the PS method. The absolute velocity of longitudinal wave in the F05 delay line is 4140 (m/s) (all at 20 °C), temperature coefficient of travel time is −3.3×10−5/°C, attenuation coefficient is 0.12+0.02 (dB/cm), and temperature coefficient of attentuation is 2.5×10−3/°C. The absolute velocity of a transverse wave in the F05 delay line is 2524 (m/s), the temperature coefficient of travel time is −4.5×10−6/°C, attenuation coefficient is 2.4+0.04 (dB/cm), the temperature coefficient of attenuation is 6×10−3/°C.