Notes on Measurement Methods of Mechanical Resonators Used in Low Temperature Physics

Abstract

Mechanical resonators like vibrating wires, grids, spheres, torsional oscillators and recently introduced tuning forks are very useful experimental tools used for the study of various physical characteristics of cryogenic liquids and gases. As the information about the physical interactions of the resonator with surrounding fluid is carried by the voltage or current, the physical quantities being measured by some technique, it is obvious that the measurement electronics and electrical connections themselves affect the precision of the measurements. The aim of this contribution is to show: (i) how the electronic circuitry used for measurements of these resonators influences the precision of measurements, (ii) how this circuitry contributes to the background of the measurements, which may lead to incorrect physical interpretation, (iii) to highlight crucial aspects of the measuring techniques applied and (iv) perhaps to offer a general recipe on how to deal with the measurement techniques for these resonators.