Simple system using one-crystal composite oscillator for internal friction and modulus measurements

The three-component composite oscillator, which has separate drive and detect transducers, is widely used in internal friction experiments for obtaining simultaneous decrement, modulus, and strain amplitude measurements. Some disadvantages of this system for measurements at low temperatures are discussed. A new system is described that uses a single-quartz composite resonator as part of the feedback loop in a simple electrical oscillator circuit. This method provides accurate measurements and is far simpler than many of the systems previously proposed. It offers definite advantages for applications at low temperatures or when the sample has to be located inside a reactor facility.