Simplified Bridge System for Measurement of Internal Friction and Fractional Variations of Young's Modulus at Kilohertz Frequencies

A simplified bridge system for measurement of internal friction and fractional variations of Young's modulus at kilohertz frequencies is described. The system, composed of commercially available components, is used with a two-part composite oscillator and is capable of measuring (logarithmic) decrements ranging from 10−7 to 10−2. Fractional variations of decrement and Young's modulus can be detected to within 0.5% and 0.1 parts per million, respectively.